human movement and fitts law Flashcards
how many possible combinations
16
factor of distance
the movement time increases with the distance
factor of width
the wider the target the faster you reach it
inverse effect
halving the width means the target is twice as hard to get to
direct effect
increasing the size of the target and decreasing the distance makes it easier and faster to hit
what is fitts law
a model of human performance
distance
amplitude of movement
width
tolerance for landing on the target
how do you calculate the index of difficulty
ID = log2 (D/W + 1)
what does the index of difficulty tell us
the same distance with a larger target or the same size with a closer distance gives a smaller index of difficulty
what is the formula for fitts law
MT = a + b * ID
what is the generalisation formula
MT = a + b *ID = a + b * log2 (D/W + 1)
speed-accuracy tradeoff
were more accurate when we move slowly and we can move faster when we dont need to be accurate
motor space
the physical area you move in to interact with a target
display space
the are of the screen where the target is shown
