According to Fitts's Law, what factor significantly affects the time required to move a cursor to a target on the screen?

Correct option is C

Fitts's Law is a predictive model of human movement in human-computer interaction (HCI). It states that the time required to move a pointer to a target depends on:
1. The distance to the target (further targets take longer to reach).
2. The size of the target (smaller targets take longer to acquire).
The law mathematically models the movement time as:

Where:
· MT= Movement time
· D = Distance to the target
· W = Width (size) of the target
· a,b = Empirical constants based on the system and user.
Thus, both distance and size are significant factors affecting movement time, making (c) the correct answer.
Important Key Points:
1. Core Principle of Fitts's Law:
· The further a target is and the smaller it is, the more time is required to acquire it.
2. Application in UI Design:
· Targets (e.g., buttons) should be large and easily accessible to reduce user interaction time.
· Important elements should be placed closer to frequently accessed areas.
3. Modern Usage:
· Fitts's Law is widely applied in designing graphical user interfaces (GUIs) and optimizing user experience (UX).
Knowledge Booster:
· Color of the Target: Affects visibility but is not related to Fitts's Law.
· Cursor Size: Does not influence movement time directly but may affect precision.
· Screen Resolution: Higher resolution may require finer movement but is not central to Fitts's Law.
· Type of Input Device: While different devices (e.g., mouse vs. trackpad) may affect overall performance, Fitts's Law specifically models the relationship between distance and size.