Chapter 6 Principles of Speed, Accuracy, and Timing Quiz

"Real World" Example of Fitts' Law

Mouse Pointers & Buttons: Large Buttons, such as "Submit" or "Cancel," are easier to click than smaller ones, especially ones placed at the edge of the screen.

"Real World" Examples of Fitt's Law

Touchscreen Keyboards: Smartphone keyboards have larger keys for frequently used letters to reduce errors.

"Real World" Examples of Fitt's Law

Automotive Car Dashboard Controls: Large, easy-to-reach knobs for adjusting volume and climate control minimize driver distraction.

"Real World" Examples of Fitt's Law

Steering Wheel Buttons: Designed for quick thumb access to reduce hand movement.

Fitts' Law

states that movement time (MT) is constant whenever the ratio of the movement amplitude (A)(distance) to target width (W) remains constant

Fitts Law

MT increases as the ratio of A to W increases by either making A larger, making W smaller, or both. Very long movements to wide targets require about the same time as very short movements to narrow targets

Fitts' Law states

describes the tendency for performers to trade speed for accuracy.

Movement time is --- related to ID.

linearly

Index difficulty

the difficulty of the various combinations of amplitude (A) and width (W)

Speed-accuracy trade off:

The tendency for accuracy decreases as the movement speed or velocity increases and vice versa. The tendency for people to sacrifice or trade off speed to maintain acceptable levels of accuracy as one of the most fundamental principles of movement behavior.

What does Schmidt's law state and provide a "real world" example.

It describes the effects of movement time and distance when errors are made. Throwing a dart, typing on a keyboard, basketball free throw.

Schmidt's Law

describes the effects of movement time and distance when errors are made.

"Real World Examples of Schmidt's Law"

Throwing a Dart: If you take your time aiming, your throw is more accurate.

"Real World Examples of Schmidt's Law"

Tying on a keyboard: If you type too fast, you're more likely to make typos because your finger movements become less controlled.

Real Word Examples of Schmidt's Law"

Basketball Free Throw: A player shooting calmly has better accuracy

At what percentage of maximum velocity might you expect performance to be most variable?

50-70%

Visual Illusions(putting)

Aiming at targets, such as throwing darts at a bullseye, putting a golf ball toward a hole can be influenced greatly by its immediate visual environment.

Putting

Participants who putted toward a hole surrounded by a ring of small circles improved their performance more during a practice session than did a group of participants who putted toward a hole surrounded by a ring of large circles. Practice with perceptually larger holes produced better learning than with the smaller-looking holes.

Gunslinger effect

When participants moved first, they did so more slowly than they did when they were reacting to their opponent (who had moved first), especially when kinematics such as peak velocity and the time to reach peak velocity were measured

Gunslinger Effect

•May explain why Parkinson patients have more difficulty in self-initiating movements than responding the environmental stimuli.