Fitts
What is Fitts’s Law?
This law predicts task time based on distance and target size.
Why are larger buttons easier to use on touchscreens?
Larger targets reduce movement time and increase accuracy.
Why are swipes often faster than button presses?
They require less precision and continuous motion.
What is the minimum recommended button size for touch?
7 mm (44 pixels).
Why should forms minimize text input?
Typing is slow on touchscreens and increases user fatigue.
What does Fitts’s Law help designers predict?
Average task time and interaction efficiency in interface designs.
What are the three Android touch input types?
Physical, Touch, and Hybrid.
Why is designing feedback essential in touchscreen design?
Because touchscreens provide little or no tactile feedback.
What is the recommended button size for optimal usability?
9 mm (52 pixels).
What is progressive disclosure in touchscreen design?
It is the practice of revealing information or controls only when needed to reduce clutter.
What is ID = log₂(2D / W)?
The formula for Fitts’s Law Index of Difficulty (ID)
What is a physical touch input?
Input using tactile hardware buttons.
What is a major precision issue with touchscreens?
Fingers are less precise than a mouse cursor.
Why should controls favor the left side of the screen?
It aligns better with natural thumb reach zones.
Why should designers reduce the number of taps in a task flow?
Fewer taps improve speed, reduce fatigue, and lower the chance of errors.
What does “D” represent in Fitts’s Law?
The distance to the target.
What is a touch input?
Interaction using on-screen UI buttons.
What is one UX problem with “images under glass”?
They can feel monotonous and lack physical engagement.
How can designers reduce long scrolling?
Limit content to three screen heights and use reveal buttons.
When should gestures be added to an interface?
Gestures should be added for power users after core tasks are easily accessible.
What does “W” represent in Fitts’s Law?
The width (size) of the target.
What is a hybrid touch input?
Using physical buttons to manipulate on-screen UI elements.
What are resistive touchscreens made of?
Give a pro and con too
Two layers of glass that register pressure.
They work with any input, including gloves or styluses.
They do not support multi-touch.
How do capacitive touchscreens work?
Give a pro and con too
They use a grid of conductive wires under glass to detect touch.
Multi-touch support and better light transmission.
They require conductive touch and are prone to cracking.
Why are steppers or buttons preferred for small number ranges in forms?
They reduce typing, prevent errors, and improve speed and usability on touchscreens.