Nursing Research Glossary: A Comprehensive Guide to Key Terms and Concepts

Posted on Aug 15, 2024 in Psychology and Sociology

Abstract- A brief description of a completed or proposed study, usually located at the beginning of the report or proposal.

Accessible population- The population of people available for a particular study; often a non-random subset of the target population.

Accidental sampling- Selection of the most readily available persons as study participants; also called convenience sampling.

Acquiescence response set- A bias in self-report instruments, especially in psychosocial scales, created when study participants characteristically agree with statements independent of their content.

Adjusted mean- The mean group value for the dependent variable, after statistically removing the effect of covariates.

After-only design- An experimental design in which data are collected from subjects only after an experimental intervention has been introduced.

Alpha –(1) In tests of statistical signiﬁcance, the level designating the probability of committing a Type I error; (2) in estimates of internal consistency, a reliability coefficient, as in Cronbach’s alpha.

Alternative hypothesis- In hypothesis testing, a hypothesis different from the one being tested—usually, different from the null hypothesis.

Analysis- The process of organizing and synthesizing data so as to answer research questions and test hypotheses.

Analysis of covariance (ANCOVA)- A statistical procedure used to test mean differences among groups on a dependent variable, while controlling for one or more extraneous variables (covariates).

Analysis of variance (ANOVA)- A statistical procedure for testing mean differences among three or more groups by comparing variability between groups to variability within groups.

Analysis triangulation- The use of two or more analytic techniques to analyze the same set of data.

Anonymity- Protection of participants in a study such that even the researcher cannot link individuals with the information provided.

Applied research- Research designed to find a solution to an immediate practical problem.

Assent- The affirmative agreement of a vulnerable subject (e.g., a child) to participate in a study.

Associative relationship- An association between two variables that cannot be described as causal (i.e., one variable causing the other).

Assumption- A basic principle that is accepted as being true based on logic or reason, but without proof or veriﬁcation.

Asymmetric distribution- A distribution of data values that is skewed, that is, has two halves that are not mirror images of each other.

Attribute variables- Pre-existing characteristics of study participants, which the researcher simply observes or measures.

Attrition- The loss of participants over the course of a study, which can create bias and undermine internal validity by changing the composition of the sample—particularly if more participants are lost from one group (e.g., experimental) than another(e.g., controls).

Audio-CASI (computer-assisted self-inter- view)

An approach to collecting self-report data in which respondents listen to questions being read over headphones and respond by entering information directly onto a computer.

Auditability-The extent to which an external reviewer or reader can follow a qualitative researcher’s steps and decisions and draw conclusions about the analysis and interpretation of the data.

Audit trail- The systematic documentation of material that allows an independent audit or of a qualitative study to draw conclusions about the trustworthiness of the data.

Auto-ethnography- Ethnographic studies in which researchers study their own culture or group.

Axial coding- The second level of coding in a grounded theory study using the Strauss and Corbin approach, involving the process of categorizing, recategorizing, and condensing all ﬁrst level codes by connecting a category and its subcategories.

Back-translation- The translation of a translated text back into the original language, so that a comparison of the original and back-translated version can be made.

Baseline data- Data collected before an intervention, including pre treatment data from a measure of the dependent variable.

Basic research- Research designed to extend the knowledge base in a discipline for the sake of knowledge production or theory construction, rather than for solving an immediate problem.

Basic social process (BSP)-The central social process emerging through an analysis of grounded theory data.

Before–after design- An experimental design in which data are collected from research subjects before and after the introduction of an experimental intervention.

Beneﬁcence- A fundamental ethical principle that seeks to prevent harm and exploitation of, and maximize beneﬁts for, study participants.

Beta- (1) In multiple regression, the standardized coefficients indicating the relative weights of the independent variables in the regression equation; (2) in statistical testing, the probability of a Type II error.

Between-subjects design- A research design in which there are separate groups of people being compared (e.g., smokers and non-smokers).

Bias- Any inﬂuence that produces a distortion in the results of a study.

Bimodal distribution- A distribution of data values with two peaks (high frequencies).

Bivariate statistics- Statistics derived from analyzing two variables simultaneously to assess the empirical relationship between them.

“Blind” review- The review of a manuscript or proposal such that neither the author nort he reviewer is identiﬁed to the other party.

Blinding- The masking or withholding of information (e.g., from research subjects, research personnel, or reviewers) to reduce the possibility of certain biases.

Borrowed theory- A theory borrowed from another discipline to guide nursing practice or research.

Bracketing- In phenomenological inquiries, the process of identifying and holding in abeyance any preconceived beliefs and opinions about the phenomena understudy.

Bricolage- The tendency in qualitative research to assemble a complex array of data from a variety of sources, using a variety of methods.

Calendar question– A question used to obtain retrospective information about the chronology of events and activities in people’s lives.

Canonical analysis- A statistical procedure for examining the relationship between two or more independent variables and two or more dependent variables.

Carry-over effect- The inﬂuence that one treatment can have on subsequent treatments.

Case-control design- A non experimental research design involving the comparison of a “case” (i.e., a person with the condition under scrutiny, such as lung cancer) and a matched control (a similar person without the condition).

Case study- A research method involving a thorough, in-depth analysis of an individual, group, institution, or other social unit.

Categorical variable- A variable with discrete values (e.g., gender) rather than values along a continuum (e.g., weight).

Category system- In observational studies, the pre speciﬁed plan for organizing and record-ing the behaviours and events under observation; in qualitative studies, the system used to sort and organize narrative data.

Causal modeling- The development and statistical testing of an explanatory model of hypothesized causal relationships among phenomena.

Causal (cause-and-effect) relationship- A relationship between two variables such that the presence or absence of one variable(the “cause”) determines the presence or absence, or value, of the other (the “effect”).

Cell- (1) The intersection of a row and column in a table with two or more dimensions; (2)in an experimental design, the representation of an experimental condition in a schematic diagram.

Census- A survey covering an entire population.

Central (core) category- The main theme of the research in a Strauss and Corbin grounded theory analysis.

Central tendency- A statistical index of the “typicalness” of a set of scores, derived from the centre of the score distribution; indexes of central tendency include the mode, median, and mean.

Chi-squared test- A nonparametric test of statistical signiﬁcance used to assess whether a relationship exists between two nominal-level variables.

Clinical relevance- The degree to which a study addresses a problem of signiﬁcance to the practice of nursing.

Clinical research- Research designed to generate knowledge to guide clinical practice in nursing and other health care ﬁelds.

Clinical trial- A study designed to assess the safety and effectiveness of a new clinical treatment, sometimes involving several phases, one of which (Phase III) is a randomized clinical trial using an experimental design and, often, a large and heterogeneous sample of subjects.

Closed-ended question- A question that offers respondents a set of mutually exclusive and jointly exhaustive alternative response options, from which the one most closely approximating the “right” answer must be chosen.

Cluster analysis- A multivariate statistical procedure used to cluster people or things based on patterns of association.

Cluster randomization- The random assignment of intact groups of subjects rather than individual subjects to treatment conditions.

Cluster sampling- A form of sampling in which large groupings (“clusters”) are selected first (e.g., nursing schools), with successive sub sampling of smaller units(e.g., nursing students).

Code of ethics- The fundamental ethical principles established by a discipline or institution to guide researchers’ conduct in research with human (or animal) subjects.

Codebook – A record documenting categorization and coding decisions.

Coding- The process of transforming raw data into standardized form for data processing and analysis; in quantitative research, the process of attaching numbers to categories; in qualitative research, the process of identifying recurring words, themes, or concepts within the data.

Coefficient alpha (Cronbach’s alpha)- A reliability index that estimates the internal consistency or homogeneity of a measure composed of several items or subparts.

Coercion-In a research context, the explicit or implicit use of threats (or excessive rewards) to gain people’s cooperation in a study.

Cohort study- A kind of trend study that focuses on a speciﬁc subpopulation (which is often an age-related subgroup) from which different samples are selected at different points in time (e.g., the cohort of nursing students who graduated between2005 and 2009).

Comparison group- A group of subjects whose scores on a dependent variable a reused to evaluate the outcomes of the group of primary interest (e.g., non smokers as a comparison group for smokers); term often used in lieu of control group when the study design is not a true experiment.

Computer-assisted personal interviewing(CAPI)- In-person interviewing in which the interviewers read questions from, and enter responses onto, a laptop computer.

Computer-assisted telephone interviewing(CATI)- Interviewing done over the telephone in which the interviewers read questions from, and enter responses onto, a computer.

Concealment- A tactic involving the unobtrusive collection of research data without participants’ knowledge or consent, used to obtain an accurate view of naturalistic behaviour when the known presence of an observer would distort the behaviour of interest.

Concept- An abstraction based on observations of or inferences from behaviours or characteristics (e.g., stress pain).

Conceptual deﬁnition- The abstract or theoretical meaning of the concepts being studied.

Conceptual ﬁle- A manual method of organizing qualitative data, by creating ﬁle folders for each category in the coding scheme and inserting relevant excerpts from the data.

Conceptual model- Interrelated concepts or abstractions assembled together in a rational scheme by virtue of their relevance to a common theme; sometimes called conceptual framework.

Conceptual utilization– The use of research ﬁndings in a general, conceptual way to broaden one’s thinking about an issue without putting the knowledge to any speciﬁc, documentable use.

Concurrent validity- The degree to which scores on an instrument are correlated with some external criterion, measured at the same time.

Conﬁdence interval- The range of values within which a population parameter is estimated to lie.

Conﬁdence level- The estimated probability that a population parameter lies within a given conﬁdence interval.

Conﬁdentiality- Protection of participants in a study such that individual identities are not linked to information provided and are never publicly divulged.

Conﬁrmability- A criterion for evaluating the quality of qualitative research, referring to the objectivity or neutrality of the data or the analysis and interpretation.

Conﬁrmatory factor analysis- A factor analysis, based on maximum likelihood estimation, designed to conﬁrm a hypothesized measurement model.

Consent form- A written agreement signed by a study participant and a researcher concerning the terms and conditions of voluntary participation in a study.

Constant comparison- A procedure often used in a grounded theory analysis where in newly collected data are compared in an ongoing fashion with data obtained earlier, to refine theoretically relevant categories.

Constitutive pattern- In hermeneutic analysis, a pattern that expresses the relationships among relational themes and is present in all the interviews or texts.

Construct– An abstraction or concept that is deliberately invented (constructed) by researchers for a scientiﬁc purpose (e.g., health locus of control).

Construct validity- The degree to which an instrument measures the construct under investigation.

Consumer- An individual who reads, reviews, and critiques research ﬁndings and who attempts to use and apply the ﬁndings in his or her practice.

Contact information- Information obtained from study participants in longitudinal studies that facilitates their relocation at a future date.

Contamination- The inadvertent, undesirable inﬂuence of one experimental treatment condition on another treatment condition.

Content analysis- The process of organizing and integrating narrative, qualitative information according to emerging themes and concepts.

Content validity- The degree to which the items in an instrument adequately represent the universe of content for the concept being measured.

Content validity index (CVI)- An indicator of the degree to which an instrument is content valid, based on average ratings of a panel of experts.

Contingency table- A two-dimensional table that permits a cross tabulation of the frequencies of two categorical variables.

Continuous variable- A variable that can take on an inﬁnite range of values along a speciﬁed continuum (e.g., height).

Control- The process of holding constant possible inﬂuences on the dependent variable under investigation.

Control group- Subjects in an experiment who do not receive the experimental treatment and whose performance provides a baseline against which the effects of the treatment can be measured (see also comparison group).

Convenience sampling- Selection of the most readily available persons as participants in a study; also called accidental sampling.

Convergent validity- An approach to construct validation that involves assessing the degree to which two methods of measuring a construct are similar (i.e., converge).

Core variable (category)- In a grounded theory study, the central phenomenon that issued to integrate all categories of the data.

Correlation- An association or connection between variables, such that variation in one variable is related to variation in another.

Correlation coefficient- An index summarizing the degree of relationship between variables, typically ranging from +1.00 (for a perfect positive relationship) through 0.0(for no relationship) to -1.00 (for a perfect negative relationship).

Correlation matrix- A two-dimensional display showing the correlation coefficients between all pairs of a set of study variables.

Correlational research- Research that explores the interrelationships among variables of interest without any active intervention by the researcher.

Cost–beneﬁt analysis- An evaluation of the monetary costs of a program or intervention relative to the monetary gains attributable to it.

Counterbalancing- The process of systematically varying the order of presentation of stimuli or treatments to control for ordering effects, especially in a crossover design.

Counterfactual- The condition or group used as a basis of comparison in a study.

Covariate- A variable that is statistically con-trolled (held constant) in analysis of covariance. The covariate is typically an extraneous, confounding inﬂuence on the dependent variable or a pre intervention measure of the dependent variable.

Covert data collection- The collection of information in a study without participants’ knowledge.

Cramér’s V – An index describing the magnitude of the relationship between nominal-level data, used when the contingency table to which it is applied is larger than 2×2.

Credibility- A criterion for evaluating data quality in qualitative studies, referring to conﬁdence in the truth of the data.

Criterion sampling- A sampling approach in qualitative research that involves selecting cases that meet a predetermined criterion of importance.

Criterion variable- The criterion against which the effect of an independent variable is tested; sometimes used instead of dependent variable.

Criterion-related validity– The degree to which scores on an instrument are correlated with some external criterion.

Critical case sampling- A sampling approach used by qualitative researchers involving the purposeful selection of cases that are especially important or illustrative.

Critical ethnography- An ethnography that focuses on raising consciousness in the group or culture under study in the hope of effecting social change.

Critical incident technique- A method of obtaining data from study participants by in-depth exploration of speciﬁc incidents and behaviours related to the topic understudy.

Critical region- The area in the sampling distribution representing values that are “improbable” if the null hypothesis is true.

Critical theory- An approach to viewing the world that involves a critique of society, with the goal of envisioning new possibilities and effecting social change.

Critique- An objective, critical, and balanced appraisal of a research report’s various dimensions (e.g., conceptual, methodologic, ethical).

Cronbach’s alpha- A widely used reliability index that estimates the internal consistency or homogeneity of a measure com-posed of several subparts; also called coefficient alpha.

Crossover design- An experimental design in which one group of subjects is exposed to more than one condition or treatment in random order; sometimes called a repeated-measures design.

Cross-sectional design– A study design in which data are collected at one point in time; sometimes used to infer change overtime when data are collected from different age or developmental groups.

Cross tabulation- A determination of the number of cases occurring when two variables are considered simultaneously (e.g., gender—male/female– cross tabulated with smoking status—smoker/non-smoker). The results are typically presented in a table with rows and columns divided according to the values of the variables.

Data- The pieces of information obtained in the course of a study (singular is datum).

Data analysis- The systematic organization and synthesis of research data and, in most quantitative studies, the testing of research hypotheses using those data.

Data collection- The gathering of information to address a research problem.

Data collection protocols- The formal procedures researchers develop to guide the collection of data in a standardized fashion inmost quantitative studies.

Data saturation- See saturation.

Data set- The total collection of data on all variables for all study participants.

Data source triangulation- The use of multiple data sources for the purpose of validating conclusions.

Debrieﬁng- Communication with study participants after participation is complete regarding various aspects of the study.

Deception- The deliberate withholding of information, or the provision of false information, to study participants, usually to reduce potential biases.

Deductive reasoning- The process of developing speciﬁc predictions from general principles (see also inductive reasoning).

Degrees of freedom- A concept used in statistical testing, referring to the number of sample values free to vary (e.g., with a given sample mean, all but one value would be free to vary); degrees of freedom is often N- 1, but different formulas are relevant for different tests.

Delphi technique- A method of obtaining written judgments from a panel of experts about an issue of concern; experts are questioned individually in several rounds, with a summary of the panel’s views circulated between rounds, to achieve some consensus.

Demonstration- A test of an innovative intervention, often on a large scale, to determine its effectiveness and the desirability of making practice or policy changes.

Dependability- A criterion for evaluating data quality in qualitative data, referring to the stability of data over time and over conditions.

Dependent variable- The variable hypothesized to depend on or be caused by another variable (the independent variable); the out-come variable of interest.

Descriptive phenomenology- A type of phenomenology, developed by Husserl, that emphasizes the careful description of ordinary conscious experience of everyday life.

Descriptive research- Research studies that have as their main objective the accurate portrayal of the characteristics of persons, situations, or groups, and/or the frequency with which certain phenomena occur.

Descriptive statistics- Statistics used to describe and summarize data (e.g., means, standard deviations).

Descriptive theory- A broad characterization that thoroughly accounts for a single phenomenon.

Determinism- The belief that phenomena are not haphazard or random, but rather have antecedent causes; an assumption in the positivist paradigm.

Deviation score- A score computed by subtracting the mean of a set of scores from an individual score.

Dichotomous variable- A variable having only two values or categories (e.g., sex).

Directional hypothesis- A hypothesis that makes a speciﬁc prediction about the direction and nature of the relationship between two variables.

Discourse analysis- A qualitative tradition, from the discipline of sociolinguistics, that seeks to understand the rules, mechanisms, and structure of conversations.

Discrete variable- A variable with a ﬁnite number of values between two points.

Discriminate function analysis- A statistical procedure used to predict group member-ship or status on a categorical (nominal level) variable on the basis of two or more independent variables.

Discriminate validity- An approach to construct validation that involves assessing the degree to which a single method of measuring two constructs yields different results(i.e., discriminates the two).

Disproportionate sample- A sample in which the researcher samples differing proportions of study participants from different population strata to ensure adequate representation from smaller strata.

Domain- In ethnographic analysis, a unit or broad category of cultural knowledge.

Double-blind experiment- An experiment in which neither the subjects nor those who administer the treatment know who is in the experimental or control group.

Dummy variable- Dichotomous variables created for use in many multivariate statistical analyses, typically using codes of 0 and1 (e.g., female =1, male=0).

Ecological psychology- A qualitative tradition that focuses on the environment’s inﬂuence on human behaviour and attempts to identify principles that explain the interdependence of humans and their environmental context.

Editing analysis style- An approach to the analysis of qualitative data, in which researchers read through texts in search of meaningful segments and develop a categorization scheme that is used to sort and organize the data.

Effect size- A statistical expression of the magnitude of the relationship between two variables, or the magnitude of the difference between two groups, with regard to some attribute of interest.

Eigen value- In factor analysis, the value equal to the sum of the squared weights for each factor.

Electronic database- Bibliographic ﬁles that can be accessed by computer for the purpose of conducting a literature review.

Element- The most basic unit of a population from which a sample is drawn typically humans in nursing research.

Eligibility criteria- The criteria used to designate the speciﬁc attributes of the target population, and by which people are selected for participation in a study.

Emergent design- A design that unfolds in the course of a qualitative study as the researcher makes ongoing design decisions reﬂecting what has already been learned.

Emergent ﬁt- A concept in grounded theory that involves comparing new data and new categories with previously existing conceptualizations (e.g., from the literature).

Emic perspective- A term used by ethnographers to refer to the way members of a culture themselves view their world; the” insider’s view.”

Empirical evidence- Evidence rooted in objective reality and gathered using one’s senses as the basis for generating knowledge.

Endogenous variable- In path analysis, a variable whose variation is determined by other variables within the model.

Error of measurement- The deviation between true scores and obtained scores of a measured characteristic.

Error term- The mathematic expression (typically in a regression analysis) that represents all unknown or immeasurable attributes that can affect the dependent variable.

Estimation procedures- Statistical procedures that have as their goal the estimation of population parameters based on sample statistics.

Eta squared- In ANOVA, a statistic calculated to indicate the proportion of variance in the dependent variable explained by the independent variables, analogous to R² in multiple regression.

Ethics- A system of moral values that is concerned with the degree to which research procedures adhere to professional, legal, and social obligations to the study participants.

Ethnography- A branch of human inquiry, associated with the ﬁeld of anthropology, that focuses on the culture of a group of people, with an effort to understand the worldview of those under study.

Ethnomethodology- A branch of human inquiry, associated with sociology, that focuses on the way in which people make sense of their everyday activities and come to behave in socially acceptable ways.

Ethnonursing research- The study of human cultures, with a focus on a group’s beliefs and practices relating to nursing care and related health behaviours.

Etic perspective- A term used by ethnographers to refer to the “outsider’s” view of the experiences of a cultural group.

Evaluation research- Research that investigates how well a program, practice, or policy is working.

Event sampling- In observational studies, a sampling plan that involves the selection of integral behaviours or events.

Evidence hierarchy- A ranked arrangement of the validity and dependability of evidence based on the rigour of the design that produced it.

Evidence-based practice- A practice that involves making clinical decisions on the best available evidence, with an emphasis on evidence from disciplined research.

Ex post facto research- Non experimental research conducted after variations in the independent variable have occurred in the natural course of events and, therefore, any causal explanations are inferred “after the fact.”

Exclusion criteria-The criteria that specify characteristics that a population does not have.

Exogenous variable- In path analysis, a variable whose determinants lie outside the model.

Experiment- A study in which the researcher controls (manipulates) the independent variable and in a true experiment randomly assigns subjects to different conditions.

Experimental group- Subjects in a study who receive the experimental treatment or intervention.

Experimental intervention- (experimental treatment) See intervention; treatment

Exploratory factor analysis- A factor analysis undertaken to determine the underlying dimensionality of a set of variables.

Exploratory research- A study that explores the dimensions of a phenomenon or that develops or reﬁnes hypotheses about relationships between phenomena.

External criticism- In historical research, the systematic evaluation of the authenticity and genuineness of data.

External validity- The degree to which study results can be generalized to settings or samples other than the one studied.

Extraneous variable- A variable that confounds the relationship between the independent and dependent variables and that needs to be controlled either in the research design or through statistical procedures to clarify relationships.

Extreme case sampling- A sampling approach used by qualitative researchers that involves the purposeful selection of the most extreme or unusual cases.

Extreme response set- A bias in self report instruments, especially in psychosocial scales, created when participants select extreme response alternatives (e.g., “strongly agree”), independent of the item’s content.

F –ratio- The statistic obtained in several statistical tests (e.g., ANOVA) in which variation attributable to different sources (e.g., between groups and within groups) is compared.

Face validity- The extent to which a measuring instrument looks as though it is measuring what it purports to measure.

Factor analysis- A statistical procedure for reducing a large set of variables into a smaller set of variables with common characteristics or underlying dimensions.

Factor extraction- The ﬁrst phase of a factor analysis, which involves the extraction of as much variance as possible through the successive creation of linear combinations of the variables in the analysis.

Factor loading- In factor analysis, the weight associated with a variable on a given factor.

Factor rotation- The second phase of factor analysis, during which the reference axes for the factors are moved such that variables more clearly align with a single factor.

Factor score- A person’s score on a latent variable (factor).

Factorial design- An experimental design in which two or more independent variables are simultaneously manipulated, permit-ting a separate analysis of the main effects of the independent variables, plus the inter-action effects of those variables.

Feasibility study- A small-scale test to deter-mine the feasibility of a larger study (see also

pilot study).

Feminist research- Research that seeks to understand, typically through qualitative approaches, how gender and a gendered social order shapes women’s lives and their consciousness.

Field diary- A daily record of events and conversations in the ﬁeld; also called a log

Field notes- The remarks taken by researchers describing the unstructured observations they have made in the ﬁeld and their interpretation of those observations.

Field research- Research in which the data are collected “in the ﬁeld” from individuals in their normal roles, with the aim of under-standing the practices, behaviours, and beliefs of individuals or groups as they normally function in real life.

Fieldwork- The activities undertaken by researchers (usually qualitative researchers)to collect data out in the ﬁeld (i.e., in natural settings outside the research environment).

Findings- The results of the analysis of research data.

Fisher’s exact test- A statistical procedure used to test the signiﬁcance of the difference in proportions, used when the sample size is small or cells in the contingency table have no observations.

Fit- In grounded theory analysis, the process of identifying characteristics of one piece of data and comparing them with the characteristics of another datum to determine similarity.

Fittingness- In an assessment of the transfer-ability of ﬁndings from a qualitative study, the degree of congruence between the research sample and another group or set-ting of interest.

Fixed alternative question- A question that offers respondents a set of pre speciﬁed responses, from which the respondent must choose the alternative that most closely approximates the correct response.

Focus group interview- An interview with agroup of individuals assembled to answer questions on a given topic.

Focused interview- A loosely structured inter- view in which an interviewer guides the respondent through a set of questions using a topic guide; also called a semi structured interview.

Follow-up study- A study undertaken to deter-mine the outcomes of individuals with a speciﬁed condition or who have received a speciﬁed treatment.

Forced-choice question- A question that requires respondents to choose between two statements that represent polar positions or characteristics.

Formal grounded theory- A theory developed at a highly abstract level of theory by compiling several substantive grounded theories.

Framework – The conceptual underpinnings of a study; often called a theoretical framework in studies based on a theory, or a conceptual framework in studies rooted in a speciﬁc conceptual model.

Frequency distribution – A systematic array of numeric values from the lowest to the highest, together with a count of the number of times each value was obtained.

Frequency polygon – Graphic display of a frequency distribution in which dots connected by a straight line indicate the number of times score values occur in a dataset.

Friedman test – A nonparametric analog of ANOVA, used with paired-groups or repeated measures situations.

Full disclosure – The communication of complete information to potential study participants about the nature of the study, the right to refuse participation, and the likely risks and benefits that would be incurred.

Functional relationship – A relationship between two variables in which it cannot be assumed that one variable caused the other, but it can be said that one variable changes values in relation to changes in the other variable.

Gaining entrée – The process of gaining access to study participants in qualitative field studies through the cooperation of key actors in the selected community or site.

Generalizability – The degree to which the research methods justify the inference that the ﬁndings are true for a broader group than study participants; in particular, the inference that the ﬁndings can be generalized from the sample to the population.

“Going native” – A pitfall in qualitative research wherein a researcher becomes too emotionally involved with participants, and therefore loses the ability to observe ration-ally and objectively.

Grand theory – A broad theory aimed at describing large segments of the physical, social, or behavioural world; also called a macrotheory

Grand tour question – A broad question asked in an unstructured interview to gain a general overview of a phenomenon on the basis of which more focused questions are subsequently asked.

Graphic rating scale – A scale in which respondents are asked to rate something (e.g., a concept or an issue) along an ordered bipolar continuum (e.g., “excellent” to “very poor”).

Grounded theory- An approach to collecting and analyzing qualitative data that aims to develop theories and theoretical propositions grounded in real world observations.

Hawthorne effect- The effect on the dependent variable resulting from subjects’ awareness that they are participants under study.

Hermeneutic circle- In hermeneutics, the qualitative circle signiﬁes a methodologic process in which, to reach understanding, there is continual movement between the parts and the whole of the text that are being analyzed.

Hermeneutics- A qualitative research tradition, drawing on interpretive phenomenology, that focuses on the lived experiences of humans and on how they interpret those experiences.

Heterogeneity- The degree to which objects are dissimilar (i.e., characterized by high variability) with respect to some attribute.

Hierarchical multiple regression- A multiple regression analysis in which predictor variables are entered into the equation insteps that are pre speciﬁed by the analyst.

Histogram- A graphic presentation of frequency distribution data.

Historical research- Systematic studies designed to discover facts and relationships about past events.

History threat- The occurrence of events external to an intervention (or other independent variable) but occurring concurrent with it, which can affect the dependent variable and threaten the study’s internal validity.

Homogeneity- (1)In terms of the reliability of an instrument, the degree to which its sub-parts are internally consistent (i.e., are measuring the same critical attribute); (2) more generally, the degree to which objects are similar (i.e., characterized by low variability).

Homogenous sampling- A sampling approach used by qualitative researchers involving the deliberate selection of cases with limited variation.

Hypothesis- A prediction, usually a statement of predicted relationships between variables.

Hypothesis testing- A statistical procedure that involves the comparison of empirically observed sample ﬁndings with theoretically expected ﬁndings that would be expected if the null hypothesis were true.

Impact analysis- An evaluation of the effects of a program or intervention on outcomes of interest, net of other factors inﬂuencing those outcomes.

Implementation analysis- In an evaluation, a description of the process by which a program or intervention was implemented in practice.

Implementation potential- The extent to which an innovation is amenable to implementation in a new setting, an assessment of which is usually made in an evidence-based practice (or research utilization) project.

Implied consent- Consent to participate in a study that a researcher assumes has been given based on certain actions of the participant (such as returning a completed questionnaire).

IMRAD format- The organization of a research report into four sections: the Introduction, Methods, Research, and Discussion sections.

Incidence rate- The rate of new “cases” with a speciﬁed condition, determined by dividing the number of new cases over a given period of time by the number at risk of becoming a new case (i.e., free of the condition at the outset of the time period).

Independent variable- The variable that is believed to cause or inﬂuence the dependent variable; in experimental research, the manipulated (treatment) variable.

Inductive reasoning- The process of reasoning from speciﬁc observations to more general rules (see also deductive reasoning).

Inferential statistics- Statistics that permit inferences on whether relationships observed in a sample are likely to occur in the larger population.

*“going native”

A pitfall in qualitativeresearch wherein a researcher becomes tooemotionally involved with participants, andtherefore loses the ability to observe ration-ally and objectively.

grand theory

A broad theory aimed atdescribing large segments of the physical,social, or behavioural world; also called a

macrotheory

grand tour question

A broad question askedin an unstructured interview to gain a gen-eral overview of a phenomenon on the basisof which more focused questions are subse-quently asked.

*graphic rating scale

A scale in whichrespondents are asked to rate something(e.g., a concept or an issue) along an ordered

Informant- A term used to refer to those individuals who provide information to researchers about a phenomenon understudy (usually in qualitative studies).

Informed consent- An ethical principle that requires researchers to obtain the voluntary participation of subjects, after informing them of possible risks and beneﬁts.

Inquiry audit- An independent scrutiny of qualitative data and relevant supporting documents by an external reviewer to determine the dependability and conﬁrmability of qualitative data.

Insider research- Research on a group or culture usually in an ethnography by a member of the group or culture.

Institutional Review Board (IRB)- In the United States, the name for the group of individuals from an institution who convene to review proposed and ongoing studies with respect to ethical considerations.

Instrument- The device used to collect data (e.g., questionnaire, test, observation schedule).

Instrumental utilization

Clearly identiﬁable attempts to base some speciﬁc action or intervention on the results of research ﬁndings.

Instrumentation threat- The threat to the internal validity of the study that can arise if the researcher changes the measuring instrument between two points of data collection.

Integrative review- A review of research that a masses comprehensive information on a topic, weighs pieces of evidence, and integrates information to draw conclusions about the state of knowledge.

Intensity sampling- A sampling approach used by qualitative researchers involving the purposeful selection of intense (but not extreme) cases.

Intention to treat- A principle for analyzing data that involves the assumption that each person received the treatment to which he or she was assigned; contrary to on protocol analysis

Interaction effect- The effect of two or more independent variables acting in combination (interactively) on a dependent variable rather than as unconnected factors.

Intercoder reliability- The degree to which two coders, operating independently, agree in their coding decisions.

Interdisciplinary- In a team or in research ,involves more than one discipline working together to produce a uniﬁed perspective on a problem or issue. This can ultimately lead to the creation of new knowledge.

Internal consistency- The degree to which the subparts of an instrument are all measuring the same attribute or dimension, as a measure of the instrument’s reliability.

Internal criticism- In historical research, an evaluation of the worth of the historical evidence.

Internal validity- The degree to which it can be inferred that the experimental treatment(or independent variable), rather than extraneous factors, is responsible for observed effects.

Interpretation- The process of making sense of the results of a study and examining their implications.

Interpretive phenomenology- An approach to phenomenology in which interpreting and

Understanding and not just describing human experience is stressed; also called hermeneutics.

Interrater (interobserver) reliability- The degree to which two raters or observers, operating independently, assign the same ratings or values for an attribute being measured or observed.

Interrupted time series design- See time series design.

Interval estimation- A statistical estimation approach in which the researcher establishes a range of values that are likely, within a given level of conﬁdence, to contain the true population parameter.

Interval measurement- A level of measurement in which an attribute of a variable is rank ordered on a scale that has equal distances between points on that scale (e.g., Celsius degrees).

Intervention- An experimental treatment or manipulation.

Intervention protocol- In experimental research, the speciﬁcation of exactly what the treatment and the alternative condition (the counterfactual) will be, and how treatments are to be administered.

Intervention research- A systematic research approach distinguished not so much by a particular research methodology as by a distinctive process of planning, developing, implementing, testing, and disseminating interventions.

Interview- A method of data collection in which one person (an interviewer) asks questions of another person (a respondent) ;interviews may be conducted face-to-face, by telephone, or via the use of a computer program.

Interview schedule- The formal instrument, used in structured self-report studies, that speciﬁes the wording of all questions to be asked of respondents.

Intuiting- The second step in descriptive phenomenology, which occurs when researchers remain open to the meaning attributed to the phenomenon by those who experienced it.

Inverse relationship- A relationship characterized by the tendency of high values on one variable to be associated with low values on the second variable; also called a negative relationship

Investigator triangulation- The use of two or more researchers to analyze and interpret a data set to enhance the validity of the ﬁndings.

Item- A single question on a test or questionnaire, or a single statement on an attitude or other scale (e.g., a ﬁnal examination might consist of 100 items).

Item analysis- A type of analysis used to assess whether items are tapping the same construct and are sufficiently discriminating.

Joint interview- An interview in which two or more people are interviewed simultaneously, typically using either a semi structured or an unstructured interview.

Jottings- Short notes jotted down quickly in the ﬁeld so as to not distract researchers from their observations or their role as participating members of a group.

Journal article- A report appearing in professional journals such as Nursing Research

Journal club- A group that meets (often in clinical settings) to discuss and critique research reports appearing in journals, sometimes to assess the potential use of the ﬁndings in practice.

Judgmental sampling- A type of non probability sampling method in which the researcher selects study participants based on personal judgment about who will be most representative or informative; also called purposive sampling

Kendall’s tau- A correlation coefficient used to indicate the magnitude of a relationship between ordinal-level variables.

Key informant- A person well-versed in the phenomenon of research interest and who is willing to share the information and insight with the researcher.

Keyword- An important concept or term used to search for references on a topic(e.g., in an electronic bibliographic data-base).

Known-groups technique- A technique for estimating the construct validity of an instrument through an analysis of the degree to which the instrument separates groups predicted to differ based on known characteristics or theory.

Kruskal–Wallis test- A nonparametric test used to test the difference between three or more independent groups, based on ranked scores.

Kuder–Richardson (KR-20) formula- A method of calculating an internal consistency reliability coefficient for a scaled set of items when the items are dichotomous.

Latent variable- An unmeasured variable that represents an underlying, abstract construct (usually in the context of a LISREL analysis).

Law- A theory that has accrued such persuasive empirical support that it is accepted as true (e.g., Boyle’s law of gases).

Least-squares estimation- A commonly used method of statistical estimation in which the solution minimizes the sums of squares of error terms; also called OLS (ordinary least squares).

Level of measurement- A system of classifying measurements according to the nature of the quantitative information and the type of mathematical operations to which they are amenable; the four levels are nominal, ordinal, interval, and ratio.

Level of signiﬁcance- The risk of making a Type I error in a statistical analysis, established by the researcher beforehand (e.g., the .05 level). A number that expresses the probability that the result of a given experiment or study could have occurred purely by chance.

Life history- A narrative self-report about a person’s life experiences vis-à-vis a theme of interest.

Life table analysis

A statistical procedure used when the dependent variable represents a time interval between an initial event (e.g., onset of a disease) and an end event (e.g., death); also called survival analysis

Likert scale- A composite measure of attitudes involving the summation of scores on a set of items that are rated by respondents for their degree of agreement or disagreement.

Linear regression- An analysis for predicting the value of a dependent variable by determining a straight-line ﬁt to the data that minimizes the sum of squared deviations from the line.

LISREL- The widely used acronym for linear structural relation analysis, typically used for testing causal models.

Literature review- A critical summary of research on a topic of interest, often pre-pared to put a research problem in context.

Log- In participant observation studies, the observer’s daily record of events and conversations that took place.

Logical positivism- The philosophy underlying the traditional scientiﬁc approach; see also positivist paradigm

Logistic regression- A multivariate regression procedure that analyzes relationships between multiple independent variables and categorical dependent variables; also called logit analysis

Logit- The natural log of the odds, used as the dependent variable in logistic regression; short for logistic probability unit.

Longitudinal study- A study designed to collect data at more than one point in time, in contrast to a cross-sectional study.

Macrotheory- A broad theory aimed at describing large segments of the physical, social, or behavioural world; also called a grand theory

Main effects- In a study with multiple independent variables, the effects of a single independent variable on the dependent variable.

Manifest variable- An observed, measured variable that serves as an indicator of an underlying construct (i.e., a latent variable), usually in the context of a LISREL analysis.

Manipulation- An intervention or treatment introduced by the researcher in an experimental or quasi-experimental study to assess its impact on the dependent variable.

Manipulation check – In experimental studies, a test to determine whether the manipulation was implemented as intended.

Mann-Whitney U test- A nonparametric statistic used to test the difference between two independent groups, based on ranked scores.

MANOVA- See multivariate analysis of variance

Matching- The pairing of subjects in one group with those in another group, based on their similarity on one or more dimension, to enhance the overall similarity of comparison groups.

Maturation threat- A threat to the internal validity of a study that results when changes to the outcome measure (dependent variable) result from the passage of time.

Maximum likelihood estimation- An estimation approach (sometimes used in lieu of the least-squares approach) in which the estimators are ones that estimate the parameters most likely to have generated the observed measurements.

Maximum variation sampling- A sampling approach used by qualitative researchers involving the purposeful selection of cases with a wide range of variation.

McNemar test- A statistical test for comparing differences in proportions when values are derived from paired (non independent)groups.

Mean- A descriptive statistic that is a measure of central tendency, computed by summing all scores and dividing by the number of subjects.

Measurement- The assignment of numbers to objects according to speciﬁed rules to characterize quantities of an attribute.

Measurement model- In LISREL, the model that stipulates the hypothesized relationships among the manifest and latent variables.

Median- A descriptive statistic that is a measure of central tendency, representing the exact middle value in a score distribution; the value above and below which 50% of the scores lie.

Median test- A nonparametric statistical test involving the comparison of median values of two independent groups to determine whether the groups are from populations with different medians.

Mediating variable- A variable that mediates or acts like a “go-between” in a chain linking two other variables (e.g., coping skills mediate the relationship between stressful events and anxiety).

Member check – A method of validating the credibility of qualitative data through debrieﬁngs and discussions with informants.

Meta-analysis- A technique for quantitatively integrating the ﬁndings from multiple studies on a given topic.

Meta-matrix- A device sometimes used in mixed-method studies that permits researchers to recognize important patterns and themes across data sources and to develop hypotheses.

Metasynthesis- The theories, grand narratives, generalizations, or interpretive translations produced from the integration or comparison of ﬁndings from multiple qualitative studies.

Method triangulation- The use of multiple methods of data collection about the same phenomenon to enhance the validity of the ﬁndings.

Methodologic notes- In observational ﬁeld studies, the researcher’s notes about the methods used in collecting data.

Methodologic research-Research designed to develop or reﬁne methods of obtaining, organizing, or analyzing data.

Methods (research)- The steps, procedures, and strategies for gathering and analyzing data in a research investigation.

Middle-range theory- A theory that focuses on only a piece of reality or human experience involving a selected number of concepts (e.g., theories of stress).

Minimal risk – Anticipated risks that are no greater than those ordinarily encountered in daily life or during the performance of routine tests or procedures.

Missing values- Values missing from a dataset for some study participants, due, for example, to refusals, researcher error, or skip patterns in an instrument.

Mixed-mode strategy- An approach to collecting survey data in which efforts are ﬁrst made to conduct the interview by telephone, but then in-person interviewing is used if a telephone interview cannot be completed.

Modality- A characteristic of a frequency distribution describing the number of peaks(i.e., values with high frequencies).

Mode- A descriptive statistic that is a measure of central tendency; the score or value that occurs most frequently in a distribution of scores.

Model- A symbolic representation of concepts or variables and interrelationships among them.

Moderator effect- The effect that a third variable (a moderator variable) has on the relationship between the independent and dependent variables.

Mortality threat- A threat to the internal validity of a study, referring to the differential loss of participants (attrition) from different groups.

Multidisciplinary- In a team or in research, involves more than one discipline offering their distinct perspectives on a problem orissue

Multimethod (mixed-method) research- Generally, research in which multiple approaches are used to address a problem; often used to designate studies in which both qualitative and quantitative data are collected and analyzed.

Multimodal distribution- A distribution of values with more than one peak (high frequency).

Multiple classiﬁcation analysis- A variant of multiple regression and ANCOVA that yields group means on the dependent variable adjusted for the effects of covariates.

Multiple comparison procedures- Statistical tests, normally applied after an ANOVA indicates statistically significant group differences, that compare different pairs of groups; also called post hoc tests

Multiple correlation coefﬁcient- An index that summarizes the degree of relationship between two or more independent variables and a dependent variable.

Multiple regression analysis- A statistical procedure for understanding the simultaneous effects of two or more independent(predictor) variables on a dependent variable.

Multistage sampling- A sampling strategy that proceeds through a set of stages from larger to smaller sampling units (e.g., from states, to nursing schools, to faculty members).

Multitrait–multimethod matrix method- A method of establishing the construct validity of an instrument that involves the use of multiple measures for a set of subjects; the target instrument is valid to the extent that there is a strong relationship between it and other measures purporting to measure the same attribute (convergence) and a weak relationship between it and other measures purporting to measure a different attribute (discriminability).

Multivariate analysis of variance (MANOVA)- A statistical procedure used to test the significance of differences between the means of two or more groups on two or more dependent variables, considered simultaneously.

Multivariate statistics- Statistical procedures designed to analyze the relationships among three or more variables; commonly used multivariate statistics include multiple regression, analysis of covariance, and factor analysis.

N – The symbol designating the total number of subjects (e.g., “the total N was 500”).

n- The symbol designating the number of subjects in a subgroup or cell of a study (e.g., “each of the four groups had an n of 125,for a total N of 500”).

Narrative analysis- A type of qualitative approach that focuses on the story as the object of the inquiry.

Natural experiment- A non experimental study that takes advantage of some naturally occurring event or phenomenon (e.g., an earthquake) that is presumed to have implications for people’s behaviour or condition, typically by comparing people exposed to the event with those not exposed.

Naturalistic paradigm- An alternative paradigm to the traditional positivist paradigm that holds that there are multiple interpretations of reality, and that the goal of research is to understand how individuals construct reality within their context; often associated with qualitative research.

Naturalistic setting- A setting for the collection of research data that is natural to thosebeing studied (e.g., homes, places of work, and so forth).

Needs assessment- A study designed to describe the needs of a group, a community, or an organization, usually as a guide to policy planning and resource allocation.

Negative case analysis- A method of reﬁning a hypothesis or theory in a qualitative study that involves the inclusion of cases that appear to dis conﬁrm earlier hypotheses.

Negative relationship- A relationship between two variables in which there is a tendency for higher values on one variable to be associated with lower values on the other (e.g., as temperature increases, people’s productivity may decrease); also called an inverse relationship

Negative results- Research results that fail to support the researcher’s hypotheses.

Negatively skewed distribution- An asymmetric distribution of data values with a disproportionately high number of case shaving high values—that is, falling at the upper end of the distribution; when displayed graphically, the tail points to the left.

Net effect- The effect of an independent variable on a dependent variable after controlling for the effect of one or more covariates through multiple regression or ANCOVA.

Network sampling- The sampling of participants based on referrals from others already in the sample; also called snowball sampling and nominated sampling

Nocebo effect- Adverse side effect experienced by those receiving a placebo treatment.

Nominal measurement- The lowest level of measurement involving the assignment of characteristics into categories (e.g., males, category 1; females, category 2).

Nominated sampling- A sampling method in which researchers ask early informants to make referrals to other study participants; called snowball sampling and network sampling

Nondirectional hypothesis- A research hypothesis that does not stipulate in advance the expected direction of the relationship between variables.

Non equivalent control group design- A quasi-experimental design involving a comparison group that was not developed on the basis of random assignment, but from whom pre intervention data usually are obtained to assess the initial equivalence of the groups.

Non experimental research- Studies in which the researcher collects data without intro-ducing an intervention.

Non parametric statistical tests- A class of inferential statistical tests that do not involve rigorous assumptions about the distribution of critical variables; most often used with nominal or ordinal data.

Non probability sampling- The selection of sampling units (e.g., participants) from a population using non random procedures, as in convenience, judgmental, and quota sampling.

Non recursive model- A causal model that predicts reciprocal effects (i.e., a variable can be both the cause of and an effect of another variable).

Non response bias- A bias that can result when a non random subset of people invited to participate in a study fail to participate.

Non signiﬁcant result- The result of a statistical test indicating that group differences or a relationship between variables could have occurred as a result of chance at a given level of signiﬁcance; sometimes abbreviated as NS

Normal distribution- A theoretical distribution that is bell shaped, symmetric, and not too peaked or ﬂat; also called a normal curve

Norms- Test performance standards, based on test score information from a large, representative sample.

Null hypothesis- A hypothesis stating no relationship between the variables under study; used primarily in statistical testing as the hypothesis to be rejected.

Nursing research- Systematic inquiry designed to develop knowledge about issues or phenomena important to the nursing profession and discipline.

Objectivity-The extent to which two independent researchers would arrive at similar judgments or conclusions (i.e., judgments not biased by personal values or beliefs).

Oblique rotation- In factor analysis, a rotation of factors such that the reference axes are allowed to move to acute or oblique angles, and hence the factors are allowed to be correlated.

Observational notes- An observer’s in-depth descriptions about events and conversations observed in naturalistic settings.

Observational research- Studies in which data are collected by observing and recording behaviours or activities of interest.

Observed (obtained) score- The actual score or numeric value assigned to a person on a measure.

Odds- The ratio of two probabilities, namely, the probability of an event occurring to the probability that it will not occur.

Odds ratio (OR)- The ratio of one odds to another odds; used in logistic regression as a measure of association and as an estimate of relative risk.

On-protocol analysis-A principle for analyzing data that includes data only from those members of a treatment group who actually received the treatment; contrary to an intention-to-treat analysis.

One-tailed test- A test of statistical signiﬁcance in which only values at one extreme(tail) of a distribution are considered in determining signiﬁcance; used when the researcher can predict the direction of a relationship (see directional hypothesis).

Open coding- The ﬁrst level of coding in a grounded theory study, referring to the basic descriptive coding of the content of the narrative data.

Open-ended question- A question in an interview or questionnaire that does not restrict respondents’ answers to pre established alternatives.

Operational deﬁnition- The deﬁnition of a concept or variable in terms of the procedures by which it is to be measured.

Operationalization- The process of translating research concepts into measurable phenomena.

Oral history- An unstructured self-report technique used to gather personal recollections of events and their perceived causes and consequences.

Ordinal measurement- A level of measurement that rank-orders phenomena or attributes along some dimension (e.g., socioeconomic status).

Ordinary least-squares (OLS) regression- Regression analysis that uses the least-squares criterion for estimating the parameters in the regression equation.

Orthogonal rotation- In factor analysis, a rotation of factors such that the reference axes are kept at a right angle, and hence the factors remain uncorrelated.

Outcome analysis- An evaluation of what happens with regard to outcomes of interest after implementing a program or intervention, without using an experimental design to assess net effects; see also impact analysis

Outcome measure- A term sometimes used to refer to the dependent variable, that is, the measure that captures the outcome of an intervention.

Outcomes research- Research designed to document the effectiveness of health care services and the end results of patient care.

P value- In statistical testing, the probability that the obtained results are due to chance alone; the probability of committing a Type I error.

Pair matching- See matching

Panel study- A type of longitudinal study in which data are collected from the same people (a panel) at two or more points in time, often in the context of a survey.

Paradigm- A way of looking at natural phenomena that encompasses a set of philosophical assumptions and that guides one’s approach to inquiry.

Paradigm case- In a hermeneutic analysis following the precepts of Benner, a strong exemplar of the phenomenon under study, often used early in the analysis to gain understanding of the phenomenon.

Parameter- A characteristic of a population(e.g., the mean age of all Canadian citizens).

Parametric statistical tests- A class of inferential statistical tests that involve (a)assumptions about the distribution of the variables, (b) the estimation of a parameter, and (c) the use of interval or ratio measures.

Participant- See study participant

Participant observation- A special approach to collecting observational data in which researchers immerse themselves in the world of study participants and participate in that world in so far as possible.

Participatory action research- A research approach with an ideological perspective based on the premise that the use and production of knowledge can be political and used to exert power.

Path analysis- A regression-based procedure for testing causal models, typically using non experimental data.

Path coefficient- The weight representing the impact of one variable on another in a path analytic causal model.

Path diagram- A graphic representation of the hypothesized linkages and causal ﬂow among variables in a causal relationship.

Pearson’s r – A widely used correlation coefficient designating the magnitude of the relationship between two variables measured on at least an interval scale; also called the product–moment correlation

Peer debrieﬁng- Sessions with peers to review and explore various aspects of a study—typically in a qualitative study.

Peer reviewer- A person who reviews and critiques a research report or proposal, who himself or herself is a researcher (usually working on similar types of research problems as those under review), and who makes a recommendation about publishing or funding the research.

Perfect relationship- A correlation between two variables such that the values of one variable permit perfect prediction of the values of the other; designated as 1.00 or 1.00.

Persistent observation- In qualitative research, the researcher’s intense focus on the aspects of a situation that are relevant to the phenomena being studied.

Person triangulation- The collection of data from different levels of persons, with the aim of validating data through multiple perspectives on the phenomenon.

Personal interview- face-to-face interview between an interviewer and a respondent.

Personal notes- In ﬁeld studies, written comments about the observer’s own feelings during the research process.

Phenomenology- A qualitative research tradition, with roots in philosophy and psychology, that focuses on the lived experience of humans.

Phenomenon- The abstract concept understudy, most often used by qualitative researchers in lieu of the term “variable.”

Phi coefficient- A statistical index describing the magnitude of the relationship between two dichotomous variables.

Photo elicitation- An interview stimulated and guided by photographic images.

Pilot study- A small-scale version, or trial run, done in preparation for a major study.

Placebo- A sham or pseudo-intervention, often used as a control condition.

Placebo effect- Changes in the dependent variable attributable to the placebo condition.

Point estimation- A statistical estimation procedure in which the researcher uses information from a sample to estimate the single value (statistic) that best represents the value of the population parameter.

Point prevalence rate- The number of people with a condition or disease divided by the total number at risk, multiplied by the number of people for whom the rate is being established (e.g., per 1000 population).

Population- The entire set of individuals or objects having some common characteristics (e.g., all RNs in South Africa); some-times called a universe

Positive relationship- A relationship between two variables in which there is a tendency for high values on one variable to be associated with high values on the other (e.g., as physical activity increases, pulse rate also increases).

Positive results- Research results that are consistent with the researcher’s hypotheses.

Positively skewed distribution- An asymmetric distribution of values with a disproportionately high number of cases having low values—that is, falling at the lower end of the distribution; when displayed graphically, the tail points to the right.

Positivist paradigm- The traditional paradigm underlying the scientiﬁc approach, which assumes that there is a ﬁxed, orderly reality that can be objectively studied; often associated with quantitative research.

Poster session- A session at a professional conference in which several researchers simultaneously present visual displays summarizing their studies, while conference attendees circulate around the room perusing the displays.

Post hoc test- A test for comparing all possible pairs of groups following a signiﬁcant test of overall group differences (e.g., in an ANOVA).

Post positivist paradigm- A modiﬁcation of the traditional positivist paradigm that acknowledges the impossibility of total objectivity; post positivists appreciate the impediments to knowing reality with certainty and therefore seek probabilistic evidence.

Pos t test- The collection of data after introducing an experimental intervention.

Post test-only design- An experimental design in which data are collected from subjects only after the experimental intervention has been introduced; also called an after-only design

Power- A research design’s ability to detect relationships that exist among variables.

Power analysis- A procedure for estimating either the likelihood of committing a Type II error or sample size requirements.

Prediction- The use of empirical evidence to make forecasts about how variables will behave in a new setting and with different individuals.

Predictive validity- The degree to which an instrument can predict some criterion observed at a future time.

Predictor variables- In a regression analysis(and other multivariate analyses), the independent variables entered into the analysis to predict the dependent variable.

Pre experimental design- A research design that does not include mechanisms to compensate for the absence of either randomization or a control group.

Pre test- (1) The collection of data before the experimental intervention; sometimes called baseline data; (2) the trial administration of a newly developed instrument to identify ﬂaws or assess time requirements.

Pre test–post test design- An experimental design in which data are collected from research subjects both before and after introducing the experimental intervention; also called a before–after design

Prevalence study- A study undertaken to determine the prevalence rate of some condition (e.g., a disease or behaviour, such as smoking) at a particular point in time.

Primary source- First-hand reports of facts, ﬁndings, or events; in research, the primary source is the original research report pre-pared by the investigator who conducted the study.

Principal investigator (PI)- The person who is the lead researcher and who will have primary responsibility for overseeing the project.

Probability sampling- The selection of sampling units (e.g., participants) from a population using random procedures, as in simple random sampling, cluster sampling, and systematic sampling.

Probing- Eliciting more useful or detailed information from a respondent in an inter-view than was volunteered in the ﬁrst reply.

Problem statement- The statement of the research problem, often phrased in the form of a research question.

Process analysis- An evaluation focusing on the process by which a program or intervention gets implemented and used in practice.

Process consent- In a qualitative study, an on going, transactional process of negotiating consent with study participants, allowing them to play a collaborative role in the decision making regarding their continued participation.

Product–moment correlation coefficient(r )- A widely used correlation coefficient, designating the magnitude of the relationship between two variables measured on at least an interval scale; also called Pearson’s r

Projective technique- A method of measuring psychological attributes (values, attitudes, personality) by providing respondents with unstructured stimuli to which to respond.

Prolonged engagement- In qualitative research, the investment of sufﬁcient time during data collection to have an in-depth understanding of the group under study, thereby enhancing data credibility.

Proportional hazards model- A model applied in multivariate analyses in which independent variables are used to predict the risk (hazard) of experiencing an event at a given point in time.

Proportionate sample- A sample that results when the researcher samples from different strata of the population in proportion to their representation in the population.

Proposal- A document specifying what the researcher proposes to study; it communicates the research problem, its signiﬁcance, planned procedures for solving the problem, and, when funding is sought, how much the study will cost.

Prospective design- A study design that begins with an examination of presumed causes (e.g., cigarette smoking) and then goes forward in time to observe presumed effects (e.g., lung cancer).

Psychometric assessment- An evaluation of the quality of an instrument, based primarily on evidence of its reliability and validity.

Psychometrics- The theory underlying principles of measurement and the application of the theory in the development of measuring tools.

Purposive (purposeful) sampling- A non-probability sampling method in which the researcher selects participants based on personal judgment about which ones will be most representative or informative; also called judgmental sampling

Q sort- A data collection method in which participants sort statements into a number of piles (usually 9 or 11) along a bipolar dimension (e.g., most like me/least like me; most useful/least useful).

Qualitative analysis- The organization and interpretation of nonnumeric data for the purpose of discovering important underlying dimensions and patterns of relationships.

Qualitative data- Information collected in narrative (nonnumeric) form, such as the transcript of an unstructured interview.

Qualitative outcome analysis (QOA)- An approach to address the gap between qualitative research and clinical practice, involving the identiﬁcation and evaluation of clinical interventions based on qualitative ﬁndings.

Qualitative research- The investigation of phenomena, typically in an in-depth and holistic fashion, through the collection of rich narrative materials using a ﬂexible research design.

Quantitative analysis- The manipulation of numeric data through statistical procedures for the purpose of describing phenomena or assessing the magnitude and reliability of relationships among them.

Quantitative data- Information collected in a quantiﬁed (numeric) form.

Quantitative research- The investigation of phenomena that lend themselves to precise measurement and quantiﬁcation, often involving a rigourous and controlled design.

Quasi-experiment- A study involving an intervention in which subjects are not randomly assigned to treatment conditions, but the researcher exercises certain controls to enhance the study’s internal validity.

Quasi-statistics- An “accounting” system used to assess the validity of conclusions derived from qualitative analysis.

Questionnaire- A method of gathering self-report information from respondents through self-administration of questions in a paper-and-pencil or computerized for-mat.

Quota sampling- The non random selection of participants in which the researcher pre speciﬁes characteristics of the sample to increase its representativeness.

r -The symbol for a bivariate correlation coefﬁcient, summarizing the magnitude and direction of a relationship between two variables.

R- The symbol for a multiple correlation coefﬁcient indicating the magnitude (but not direction) of the relationship between the dependent variable and multiple independent variables taken together.

R²- The squared multiple correlation coefﬁcient, indicating the proportion of variance in the dependent variable accounted for or explained by a group of independent variables.

Random assignment- The assignment of sub jects to treatment conditions in a manner determined by chance alone; also called randomization

Random number table- A table displaying hundreds of digits (from 0 to 9) set up in such a way that each number is equally likely to follow any other.

Random sampling- The selection of a sample such that each member of a population has an equal probability of being included.

Randomization- The assignment of subjects to treatment conditions in a manner determined by chance alone; also called random assignment

Randomized block design- An experimental design involving two or more factors (independent variables), only one of which in experimentally manipulated.

Randomized clinical trial (RCT)- A full experimental test of a new treatment, involving random assignment to treatment groups and, typically, a large and diverse sample (also known as a Phase III clinical trial).

Randomness- An important concept in quantitative research, involving having certain features of the study established by chance rather than by design or personal preference.

Range- A measure of variability, computed by subtracting the lowest value from the highest value in a distribution of scores.

Rating scale- A scale that requires ratings of an object or concept along a continuum.

Ratio measurement- A level of measurement with equal distances between scores and a true meaningful zero point (e.g., weight).

Raw data- Data in the form in which they were collected, without being coded or analyzed.

Reactivity- A measurement distortion a rising from the study participant’s awareness of being observed, or, more generally, from the effect of the measurement procedure itself.

Readability- The ease with which research documents (e.g., a questionnaire) can be read by people with varying reading skills, often empirically determined through read-ability formulas.

Receiver operating characteristic curve(ROC curve)- A method used in developing and reﬁning screening instruments to deter-mine the best cut-off point for “caseness.”

Recursive model- A path model in which the causal ﬂow is unidirectional, without any feedback loops; opposite of a non recursive model.

Refereed journal- A journal in which decisions about the acceptance of manuscripts are made based on recommendations from peer reviewers.

Reﬂective notes- Notes that document a qualitative researcher’s personal experiences, reﬂections, and progress in the ﬁeld.

Reﬂexive journal- A journal maintained by qualitative researchers during data collection and data analysis to document their self-analysis of both how they affected the research and how the research affected them.

Reﬂexivity- In qualitative studies, critical self reﬂection about one’s own biases, preferences, and preconceptions.

Regression analysis- A statistical procedure for predicting values of a dependent variable based on the values of one or more independent variables.

Relationship- A bond or a connection between two or more variables.

Relative risk – An estimate of risk of “caseness” in one group compared to another, computed by dividing the rate for one group by the rate for another.

Reliability- The degree of consistency or dependability with which an instrument measures the attribute it is designed to measure.

Reliability coefﬁcient- A quantitative index, usually ranging in value from .00 to 1.00,that provides an estimate of how reliable an instrument is; it is computed through such procedures as Cronbach’s alpha technique, the split-half technique, the test–retest approach, and inter rater approaches.

Repeated-measures design- An experimental design in which one group of subjects is exposed to more than one condition or treatment in random order; also called a crossover design

Replication- The deliberate repetition of research procedures in a second investigation for the purpose of determining if earlier results can be repeated.

Representative sample- A sample whose characteristics are comparable to those of the population from which it is drawn.

Research- Systematic inquiry that uses orderly, disciplined methods to answer questions or solve problems.

Research control- See control

Research design- The overall plan for addressing a research question, including speciﬁcations for enhancing the study’s integrity.

Research Ethics Board (REB)- A group established within Canadian universities, hospitals, and other institutions where research is conducted to ensure that ethical principles are applied to research involving human subjects.

Research hypothesis- The actual hypothesis a researcher wants to test (as opposed to the null hypothesis), stating the anticipated relationship between two or more variables.

Research methods- The techniques used to structure a study and to gather and analyze information in a systematic fashion.

Research misconduct- Fabrication, falsiﬁcation, plagiarism, or other practices that seriously deviate from those that are commonly accepted within the scientiﬁc community for proposing, conducting, or reporting research.

Research problem- A situation involving an enigmatic, perplexing, or conﬂictful condition that can be investigated through disciplined inquiry.

Research proposal-See proposal

Research question- A statement of the speciﬁc query the researcher wants to answer to address a research problem.

Research report- A document summarizing the main features of a study, including the research question, the methods used to address it, the ﬁndings, and the interpretation of the ﬁndings.

Research utilization- The use of some aspect of a study in an application unrelated to the original research.

Researcher credibility- The faith that can be put in a researcher, based on his or her training, qualiﬁcations, and experience.

Residuals- In multiple regression, the error term or unexplained variance.

Respondent- In a self-report study, the study participant responding to questions posed by the researcher.

Response rate- The rate of participation in a study, calculated by dividing the number of persons participating by the number of persons sampled.

Response set bias- The measurement error introduced by the tendency of some individuals to respond to items in characteristic ways (e.g., always agreeing), independently of the items’ content.

Results- The answers to research questions, obtained through an analysis of the collected data; in a quantitative study, the information obtained through statistical tests.

Retrospective design- A study design that begins with the manifestation of the dependent variable in the present (e.g., lung cancer) and then searches for the presumed cause occurring in the past (e.g., cigarette smoking).

Risk/beneﬁt ratio- The relative costs and beneﬁts, to an individual subject and to society at large, of participation in a study; also, the relative costs and beneﬁts of implementing an innovation.

Rival hypothesis- An alternative explanation, competing with the researcher’s hypothesis, to account for the results of a study.

Sample- A subset of a population, selected to participate in a study.

Sample size- The total number of study participants participating in a study.

Sampling- The process of selecting a portion of the population to represent the entire population.

Sampling bias- Distortions that arise when a sample is not representative of the population from which it was drawn.

Sampling distribution- A theoretical distribution of a statistic (e.g., a mean), using the values of the statistic computed from an inﬁnite number of samples as the data points in the distribution.

Sampling error- The ﬂuctuation of the value of a statistic from one sample to another drawn from the same population.

Sampling frame- A list of all the elements in the population from which the sample is drawn.

Sampling plan- The formal plan specifying a sampling method, a sample size, and procedures for recruiting subjects.

Saturation- The collection of data in a qualitative study to the point at which a sense of closure is attained because new data yield redundant information.

Scale- A composite measure of an attribute, involving the combination of several items that have a logical and empirical relationship to each other, resulting in the assignment of a score to place people on a continuum with respect to the attribute.

Scatter plot- A graphic representation of the relationship between two variables.

Scientiﬁc merit- The degree to which a study is methodologically and conceptually sound.

Scientiﬁc method- A set of orderly, systematic, controlled procedures for acquiring dependable, empirical and typically quantitative information; the methodologic approach associated with the positivist paradigm.

Screening instrument- An instrument used to determine whether potential subjects for a study meet eligibility criteria (or for deter-mining whether a person has a speciﬁed condition).

Secondary analysis- A form of research in which the data collected by one researcher are reanalyzed, usually by another investigator, to answer new research questions.

Secondary source- Second-hand accounts of events or facts; in a research context, a description of a study or studies prepared by someone other than the original researcher.

Selective coding- A level of coding in a grounded theory study that begins after the core category is discovered and involves systematically integrating relationships between the core category and other categories and validating those relationships.

Selection threat (self-selection)- A threat to the internal validity of the study resulting from pre existing differences between groups under study; the differences affect the dependent variable in ways extraneous to the effect of the independent variable.

Self-determination- A person’s ability to voluntarily decide whether or not to participate in a study.

Self-report- A method of collecting data that involves a direct report of information by the person who is being studied (e.g., by interview or questionnaire).

Semantic differential- A technique used to measure attitudes that asks respondents to rate a concept of interest on a series of bipolar rating scales.

Semi structured interview- An interview in which the researcher has listed topics to cover rather than speciﬁc questions to ask.

Sensitivity- The ability of screening instruments to correctly identify a “case” (i.e., to correctly diagnose a condition).

Sensitivity analysis- In a meta-analysis, a method to determine whether conclusions are sensitive to the quality of the studies included.

Sequential clinical trial- A clinical trial in which data are continuously analyzed and “stop rules” are used to decide when the evidence about the intervention’s efﬁcacy is sufﬁciently strong that the experiment can be stopped.

Setting- The physical location and conditions in which data collection takes place in a study.

Signiﬁcance level- The probability that an observed relationship could be caused by chance (i.e., as a result of sampling error); signiﬁcance at the .05 level indicates the probability that a relationship of the observed magnitude would be found by chance only 5 times out of 100.

Sign test- A nonparametric test for comparing two paired groups based on the relative ranking of values between the pairs.

Simple random sampling- The most basic type of probability sampling, wherein a sampling frame is created by enumerating all members of a population and then selecting a sample from the sampling frame through completely random procedures.

Simultaneous multiple regression- A multiple regression analysis in which all predictor variables are entered into the equation simultaneously; sometimes called direct or standard multiple regression.

Single-subject experiment- A study that tests the effectiveness of an intervention with a single subject, typically using a time series design.

Site- The overall location where a study is under taken.

Skewed distribution- The asymmetric distribution of a set of data values around a central point.

Snowball sampling- The selection of participants through referrals from earlier participants; also called network sampling or nominated sampling

Social desirability response set- A bias in self-report instruments created when participants have a tendency to misrepresent their opinions in the direction of answers consistent with prevailing social norms.

Solomon four-group design- An experimental design that uses a before–after design for one pair of experimental and control groups, and an after-only design for a second pair.

Space triangulation- The collection of data on the same phenomenon in multiple sites to enhance the validity of the ﬁndings.

Spearman–Brown prophecy formula- An equation for making corrections to a reliability estimate calculated by the split-half technique.

Spearman’s rank-order correlation (Spear-man’s rho)- A correlation coefﬁcient indicating the magnitude of a relationship between variables measured on the ordinal scale.

Speciﬁcity- The ability of a screening instrument to correctly identify non cases.

Split-half technique- A method for estimating internal consistency reliability by correlating scores on half of the instrument with scores on the other half.

Standard deviation- The most frequently used statistic for measuring the degree of variability in a set of scores.

Standard error- The standard deviation of a theoretical sampling distribution, such as a sampling distribution of means.

Standard scores- Scores expressed in terms of standard deviations from the mean, with raw scores transformed to have a mean of zero and a standard deviation of one; also called z scores.

Statement of purpose- A broad declarative statement of the overall aims/goals of a study.

Statistic- An estimate of a parameter, calculated from sample data.

Statistical analysis- The organization and analysis of quantitative data using statistical procedures, including both descriptive and inferential statistics.

Statistical conclusion validity- The degree to which conclusions about relationships and differences from a statistical analysis of the data are legitimate.

Statistical control- The use of statistical procedures to control extraneous inﬂuences on the dependent variable.

Statistical inference- The process of inferring attributes about the population based on information from a sample, using laws of probability.

Statistical power- The ability of the research design and analysis to detect true relation-ships among variables.

Statistical signiﬁcance- A term indicating that the results from an analysis of sample data are unlikely to have been caused by chance, at some speciﬁed level of probability.

Statistical test- An analytic tool that estimates the probability that obtained results from a sample reﬂect true population values.

Stepwise multiple regression- A multiple regression analysis in which predictor variables are entered into the equation in steps, in the order in which the increment to R is greatest.

Stipend- A monetary payment to individuals participating in a study to serve as an incentive for participation and/or to compensate for time and expenses.

Strata- Subdivisions of the population according to some characteristic (e.g., males and females); singular is stratum

Stratiﬁed random sampling- The random selection of study participants from two or more strata of the population independently.

Structural equations- Equations representing the magnitude and nature of hypothesized relations among sets of variables in a theory.

Structured data collection- An approach to collecting information from participants, either through self-report or observations, in which the researcher determines response categories in advance.

Study participant- An individual who pa-ticipates and provides information in a study.

Subgroup effect- The differential effect of the independent variable on the dependent variable for various subsets of the sample.

Subject- An individual who participates and provides data in a study; term used primarily in quantitative research.

Substantive theory- In grounded theory, a theory that is grounded in data from a single study on a speciﬁc substantive area(e.g., postpartum depression); in contrast to formal theory

Summated rating scale- A composite scale with multiple items, each of which is scored; item scores are added together to yield a total score that distributes people along a continuum (e.g., a Likert scale).

Survey research- Non experimental research in which information regarding the activities, beliefs, references, and attitudes of people is gathered by direct questioning.

Survival analysis- A statistical procedure used when the dependent variable represents a time interval between an initial event (e.g., onset of a disease) and an end event (e.g., death); also called life table analysis

Symmetric distribution- A distribution of values with two halves that are mirror images of each other; a distribution that is not skewed.

Systematic sampling- The selection of study participants such that every kth (e.g., every10th) person (or element) in a sampling frame or list is chosen.

Table of random numbers- See random number table

Tacit knowledge- Information about a culture that is so deeply embedded that members do not talk about it or may not even be consciously aware of it.

Target population- The entire population in which the researcher is interested and to which he or she would like to generalize the results of a study.

Taxonomy- In an ethnographic analysis, a sys-tem of classifying and organizing terms and concepts, developed to illuminate the internal organization of a domain and the relationship among the subcategories of the domain.

Template analysis style- An approach to qualitative analysis in which a preliminary template or coding scheme is used to sort the narrative data.

Test statistic- A statistic used to test for the statistical signiﬁcance of relationships between variables; the sampling distributions of test statistics are known for circumstances in which the null hypothesis is true; examples include chi-square, F -ratio, t, and Pearson’s r

Test–retest reliability- Assessment of the stability of an instrument by correlating the scores obtained on repeated administrations.

Testing threat- A threat to a study’s internal validity that occurs when the administration of a pre test or baseline measure of a dependent variable results in changes on the variable, apart from the effect of the independent variable.

Theme- A recurring regularity emerging from an analysis of qualitative data.

Theoretical notes- In ﬁeld studies, notes detailing the researcher’s interpretations of observed behaviour.

Theoretical sampling- In qualitative studies, the selection of sample members based on emerging ﬁndings as the study progresses to ensure adequate representation of important themes.

Theory- An abstract generalization that presents a systematic explanation about the relationships among phenomena.

Theory triangulation- The use of competing theories or hypotheses in the analysis and interpretation of data.

Thick description- A rich and thorough description of the research context in a qualitative study.

Think aloud method- A qualitative method used to collect data about cognitive processes (e.g., problem solving, decision making), involving the use of audio recordings to capture people’s reﬂections on decisions as they are being made or problems as they are being solved.

Time sampling- In observational research, the selection of time periods during which observations will take place.

Time series design- A quasi-experimental design involving the collection of data over an extended time period, with multiple data collection points both before and after an intervention.

Time triangulation- The collection of data on the same phenomenon or about the same people at different points in time to enhance the validity of the ﬁndings.

Topic guide- A list of broad question areas to be covered in a semi structured interview or focus group interview.

Transferability- The extent to which ﬁndings can be transferred to other settings or groups often used in qualitative research and analogous to generalizability in quantitative research.

Treatment- The experimental intervention under study; the condition being manipulated.

Treatment group- The group receiving the intervention being tested; the experimental group.

Trend study- A form of longitudinal study in which different samples from a population are studied over time with respect to some phenomenon (e.g., annual Gallup polls on abortion attitudes).

Triangulation- The use of multiple methods to collect and interpret data about a phenomenon so as to converge on an accurate representation of reality.

True score- A hypothetical score that would be obtained if a measure were infallible.

Trustworthiness- The degree of conﬁdence qualitative researchers have in their data, assessed using the criteria of credibility, transferability, dependability, and conﬁrmability.

T-test- A parametric statistical test for analyzing the difference between two means.

Two-tailed tests- Statistical tests in which both ends of the sampling distribution are used to determine improbable values.

Type I error- An error created by rejecting the null hypothesis when it is true (i.e., the researcher concludes that a relation-ship exists when in fact it does not a false positive).

Type II error- An error created by accepting the null hypothesis when it is false (i.e., the researcher concludes that no relationship exists when in fact it does a false negative).

Typical case sampling- An approach to sampling in qualitative research involving the selection of participants who highlight what is typical or average.

Unimodal distribution- A distribution of values with one peak (high frequency).

Unit of analysis- The basic unit or focus of a researcher’s analysis; in nursing research, the unit of analysis is typically the individual study participant.

Univariate descriptive study- A study that gathers information on the occurrence, frequency of occurrence, or average value of the variables of interest, one variable at a time, without focusing on interrelation-ships among variables.

Univariate statistics- Statistical procedures for analyzing a single variable for purposes of description.

Unstructured interview- An oral self-report in which the researcher asks a respondent questions without having a pre determined plan regarding the content or ﬂow of information to be gathered.

Unstructured observation- The collection of descriptive information through direct observation that is not guided by a formal ,pre speciﬁed plan for observing, enumerating, or recording the information.

Validity- The degree to which an instrument measures what it is intended to measure.

Validity coefﬁcient- A quantitative index, usually ranging in value from .00 to 1.00, that provides an estimate of how valid an instrument is.

Variability- The degree to which values on a set of scores are dispersed.

Variable- An attribute of a person or object that varies, that is, takes on different values(e.g., body temperature, age, heart rate).

Variance- measure of variability or dispersion, equal to the standard deviation squared.

Vignette- A brief description of an event, per-son, or situation about which respondents are asked to describe their reactions.

Visual analog scale- A scaling procedure used to measure certain clinical symptoms (e.g., pain, fatigue) by having people indicate on a straight line the intensity of the symptom.

Vulnerable subjects- Special groups of people whose rights in research studies need special protection because of their inability to provide meaningful informed consent or because their circumstances place the mat higher-than-average risk of adverse effects; examples include young children, the mentally retarded, and unconscious patients.

Weighting- A correction procedure used to arrive at population values when a disproportionate sampling design has been used.

Wilcoxon signed ranks test- A non parametric statistical test for comparing two paired groups based on the relative ranking of values between the pairs.

Wilk’s lambda- index used in discriminant function analysis to indicate the proportion of variance in the dependent variable unaccounted for by predictors

Within-subjects design- A research design in which a single group of subjects is compared under different conditions or at different points in time (e.g., before and after surgery).

Z score- A standard score, expressed in terms of standard deviations from the mean

Abstract- A brief description of a completed or proposed study, usually located at the beginning of the report or proposal.

Accessible population- The population of people available for a particular study; often a non-random subset of the target population.

Accidental sampling- Selection of the most readily available persons as study participants; also called convenience sampling