Conceptual Models & Interface Design: A Comprehensive Guide
Unit 1: Conceptual Model Formation
Visibility
Visible elements aid memory and reduce cognitive load. Converting information into visual representations minimizes the need for recall. Knowledge linked to visible objects simplifies interpretation. Short-term memory is limited, while long-term memory benefits from meaningful interpretation. Arbitrary data is difficult to retain, while significant relationships enhance memorization. Experiential learning reinforces conceptual models.
Everyday Activities
Declarative knowledge (factual) contrasts with procedural knowledge (demonstration-based). Design should consider the user’s purpose, intention, action, performance, and their perception of the world. Discrepancies can arise between user intent and available actions, and between visible representation and user expectations.
Activity Structures
Complex tasks involve sequences of actions and decisions. Shallow structures offer many simple alternatives, while deep structures have fewer, more complex choices. Interfaces should accommodate these structures without unnecessary complexity.
Errors
Errors arise from design flaws, user ignorance, or normal human fallibility. Error types include slips (automatic behavior), blunders (conscious mistakes), typing errors, description errors (inaccurate mental image), data-driven errors, associative activation errors, and loss-of-activation errors (forgetting). Design should anticipate and mitigate these errors.
Unit 2: Golden Rules of GUI Design
User Control
Provide user control by preventing unwanted actions, offering flexible interaction, enabling command cancellation, accelerating interaction, hiding technical details, and allowing direct object manipulation.
Reduce Memory Load
Minimize short-term memory demands through useful defaults and progressively disclosed information.
Consistent Interface
Maintain consistency by supporting various task contexts, providing clear indicators, and adhering to established standards.
User-Centered Design (UCD)
Prioritize the user’s perspective throughout the design process. Key steps include understanding the context of use, gathering user requirements, creating prototypes, and conducting evaluations.
UCD Implementation
Implement UCD through context analysis, user requirement specifications, prototyping, and iterative evaluations. The GUI lifecycle involves design, prototyping, assessment, implementation, and release.
User Analysis
Analyze user characteristics (novice, intermittent, expert) including intellectual knowledge, attitudes, frequency of use, age, ability, and environment.
Information Flows
Map the flow of information to understand its origin, destination, and transformations.
Internationalization
Adapt the interface for different countries, considering cultural variations in calendars, currency, units of measurement, etc.
Internationalization Rules
Ensure portability, effective user communication, and consistent operation across different locales.
Standards
Adhere to both de jure (legally mandated) and de facto (industry-accepted) standards, including programming interfaces, application communication protocols, and style guides.
Style Guides
Promote usability and consistency through established style guidelines.
Commercial Standards
Consider industry-standard look and feel and low-level guidelines.
Task Analysis
Analyze general user activities, identify key tasks, and describe how users perform them. Hierarchical task decomposition breaks down complex tasks into subtasks, considering user preferences and alternative approaches. Include operations outside the application and mental tasks. Document task frequency, potential interruptions, and error possibilities using flowcharts.
Information Gathering
Gather information through site visits, user observation, document review, and user interviews.
Semi-structured Interviews
Use an interview guide with a flexible order of questions.
Structured vs. Unstructured Interviews
Structured interviews follow a predetermined script, while unstructured interviews allow for more open-ended exploration.
Unit 3: Online Help and Documentation
Types of Support
Online tutorials, online documentation, and online help systems provide various levels of support, categorized by purpose, size, and relationship to the product.
Manuals
Printed and virtual manuals include introductory guides, reference manuals, FAQs, and quick guides.
Interactive Help
Advantages of interactive help include constant availability, space efficiency, ease of use, up-to-dateness, and user acceptance. Disadvantages include reduced learning efficacy, less readability, screen space limitations, and the need to learn the help system’s functionality.
Help Topics
Organize help topics into searchable libraries.
Context-Sensitive Help
Provide context-sensitive help within dialog boxes and widgets.
Text Messaging
Use text messages for brief suggestions and guidance.
Help Plan Design
Consider user type, content, structure, and context sensitivity when designing a help system. Limit support levels to a maximum of three.
Help Organization Standards
Maintain consistency in explanation levels, language, text quantity, paragraph length, spacing, graphics, and icons.
CUA Standards
Follow CUA standards for help access (F1 for menu information, Shift+F1 for context-sensitive help).
Interactive Demos
Use interactive demos for introductory learning, but be mindful of their length and complexity.