M9 Speed-Accuracy Tradeoffs & SA Considerations Flashcards
The size of a target in aiming tasks (“W” in Fitts’ Law)
Width
The distance between the two target centers in aiming tasks (“A” in Fitts’ Law)
Amplitude
The theoretical “difficulty” of a movement in the Fitts tapping task, or ID = log2(2A/W)
Index of difficulty
The tendency for accuracy to decrease as the movement speed or velocity of a movement increases and vice versa
Speed-accuracy trade-off
In Fitts’ Law, the y-intercept represents the movement time when:
The index of difficulty (ID) is 0
TF: According to Fitts’ Law, movement time (MT) decreases as movement amplitude decreases.
True
Which of the following Fitts tapping task conditions would have the highest degree of difficulty?
Large movement amplitude and small target width
Which of the following components of Fitts’ Law represents FASTER processing of more difficult movements?
Smaller (shallower) slope
Which of the following components of Fitts’ Law represents SLOWER processing of more difficult movements?
Larger (steeper) slope
Which of the following is/are true regarding Fitts’ Law?
-Closed loop movement
-Involves slower, feedback based movement
-Involves logarithmic relationship
Which of the following is/are true regarding Schmidt’ Law?
-Open loop movement
-Determined by measuring effective target width (variability) of fast movements
Force production increases in variability up to approximately _____ of maximal contraction
70%
TF: When performing movements requiring temporal (timing) accuracy, we tend to be more accurate at producing shorter (faster) movement times.
True
Based on the violations to speed-accuracy trade-offs we’ve seen in this lecture so far, what would you advise a baseball player working on their baseball swing?
Swing faster
TF: In Two-Phase Movement Theories, phase 1 of a movement is executed under open-loop control, without feedback.
True
TF: According to equilibrium-point control theories, when we need to reach to a target, we program the ENDPOINT of the movement
True
