Chapter 7- Speed + Accuracy Flashcards
Fitts’ Law
systematic analysis of the relationship between speed + accuracy
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Fitts’ Law scoring
number of taps during a given time, with instruction to limit errors (missed targets) to a minimum
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Fitts’ Law protocol
-subject holds a stylus, starts in center (home position), + taps between the left + right plates/targets
-task is to tap L/R/L/R as fast as possible when given a pre-determined amount of time
-taget tapping is not the only way Fitts studied this technique- could have small metal washers that subject must move from 1 location to another OR small pins from 1 hole to another -> consistent results, same equation
Fitts’ Law describe the targets
targets are typically rectangular + have “w” representing width of targets + distance (amplitude, A) representing how far apart the targets are (measured from center of each target)
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index of difficulty (ID)
the more difficult a task is, the more time it will take to complete it; determines how much time was required for each movement
larger ID = slower/faster = smaller/larger MT = less/more accuracy
Fitts’ Law
-slower
-larger MT
-less accuracy
larger target = smaller/larger ID
smaller
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speed-accuracy tradeoff
common errors occur when we try to perform a task more quickly than usual
-you are more prone to making mistakes when doing something faster rather than slower
what ages can Fitts’ Law be generalized to
people of ALL ages- always a speed-accuracy tradeoff in general
describe how limbs are affected by ID
=larger, more cumbersome limbs are, more sensitive to changes in ID
-arms/legs- very sensitive, large difference
-wrists- very little difference
-fingers- not so much
spatial accuracy
this is whether or not ball + bat come into contact
temporal accuracy
timing
-did I start swinging bat at the right time so that it arrives to come in contact with the baseball at the right time
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2 repetitive movement-timing tasks
-synchronization
-continuation
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synchronization
repetitive movement-timing tasks
goal is to produce motor action resulting in a tap that coincides with an external perceptible event/stimulus; has to do with whether or not you can tap exactly when the stimulus is occurring or opposite timing for negative synchrony
-ex: finger movement with auditory beats of a metronome
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continuous
repetitive movement-timing tasks
has to do with whether or not you can continue tapping at same pace even without the stimulus
-trial begins with series of synchronization taps, then metronome/pacing stimulus is turned off; goal is to continue tapping at the same pace
