Speed Accuracy Trade Off

Question 1

What does speed accuracy trade off mean

Answer 1

The more rapidly we makes the more inaccurate we become

Question 2

What is Fitts task

Answer 2

Fitts task

• must make consecutive rapid on two targets
• varied width of target and how far apart they were
• compare difficulty with how fast movement
  = average movement time
• as difficulty increases speed decreases

Question 3

What is Fitts law

Answer 3

Average movement time = MT

MT = a + b (log to the base 2 (2A/W))

Log to the base 2 (2A/W) - index of difficulty

A - the y axis intercept (when 2/a/w =1

B - increase in MT when 2a/w doubles or when ID increases by 1

Question 4

Explain the walking on a beam example Fitts law

Answer 4

Narrower beam = increase difficulty = vary w

Vary A (amplitude)

Question 5

What would happen if there was a small index of difficulty

Answer 5

Short movement time

Question 6

How does loop control come into Fitts law

Answer 6

Dependent on movement time

Question 7

What is the spatial speed accuracy trade off

Answer 7

When MT decreases, spatial accuracy decreases

Question 8

What is the temporal speed accuracy trade off

Answer 8

When MT decreases, temporal errors decrease