Key Concepts and Principles in Mobile App Design
What is a Prototype?
A prototype is a simulation or sample version of a final product, used for testing before launch. It’s an early version of the product.
What is the Golden Ratio?
The Golden Ratio identifies proportions that are naturally most visually appealing. This ratio, approximating 0.618 (often found in the Fibonacci sequence), has been used in design, architecture, and engineering for centuries. It’s applied to elements of a form, such as height to width, to achieve aesthetic balance.
Explain Fitt’s Law
Fitt’s Law states that the time required to move to a target is a function of the target size and distance to the target. Larger and closer targets are easier and faster to select.
Explain Parkinson’s Law
Parkinson’s Law, in the context of UX, suggests limiting the time it takes to complete a task to what users expect it to take. Meeting user expectations for task completion time is crucial.
Explain Onboarding Screens
An onboarding screen is the first interaction users have with an app. App users are often quick to abandon apps they don’t understand. In fact, 25% of users abandon an app after first use. A solid mobile app onboarding experience is critical for success because first impressions matter.
Three App Store KPIs
- Mobile Downloads
- Uninstallations
- Crashes
Three Usability Heuristics
- Visibility of System Status
- Match Between System and the Real World
- User Control and Freedom
Mobile App Navigation Elements
Navigation guides users from point A to point B, allowing them to discover and interact with the product. The menu is a core navigation element, presenting options for interaction. Menus can have different locations within the interface.
What is a CTA?
CTA stands for Call to Action.
Gamification and Three Tactics
Gamification provides the excitement of quick, repetitive rewards. Applying game-like interactions in a non-gaming setting increases engagement. Gamification can be incorporated in degrees, based on product and user needs.
Gamification tactics:
- Challenges and streaks
- Progress bars
- Badges and stickers
Define Terms and Conditions
Terms and Conditions are documents that protect the app owner by setting legally binding rules on how users can interact with the app.
Mobile App Accessibility
Accessibility refers to how easy it is for someone with a disability to interact with an app.
Impairments in the context of mobile apps:
- Visual impairments
- Hearing impairments
- Mobility impairments
- Learning impairments (with intellectual disabilities)
Three Principles of the Agile Manifesto
- Our highest priority is to satisfy the customer through early and continuous delivery of valuable software.
- Welcome changing requirements, even late in development. Agile processes harness change for the customer’s competitive advantage.
- Deliver working software frequently, from a couple of weeks to a couple of months, with a preference to the shorter timescale.
Describe the Fogg Model
The Fogg Behavior Model states that behavior happens when three elements converge: Motivation (users are motivated), Ability (users can perform the behavior), and Prompt (users are prompted at the right time).
Describe the Kano Model
The Kano Model describes the relationship between a product’s attributes and customer satisfaction. It analyzes consumer preferences for features, grouping them into categories to identify which features to prioritize during product development.
Explain the Zeigarnik Effect
The Zeigarnik Effect suggests that people remember uncompleted or interrupted tasks better than completed ones. Invite content discovery with clear signifiers of additional content. Providing artificial progress towards a goal increases the likelihood of task completion.
Explain the Peak-End Rule
The Peak-End Rule states that people judge an experience largely based on how they felt at its peak and end, not the overall average. Focus on the most intense points and the final moments of the user journey. Identify when your product is most helpful or entertaining, and design to delight the user. Remember that negative experiences are more vividly recalled than positive ones.
Explain Occam’s Razor
Occam’s Razor suggests that the best way to reduce complexity is to avoid it in the first place. Analyze each element and remove as many as possible without compromising function. Consider it complete only when no further elements can be removed. Simplify, but don’t oversimplify.