Hi all,
I am trying to have participants match the color of an object to the perceived color of an illusion - specifically, White’s Illusion. In White’s Illusion, smaller gray bars are superimposed over interlacing black and white bars, which alter the perceived shade of gray of the smaller gray bars. I am trying to have participants match the color of an object with their perceived level of gray. How might I go about doing this in builder? Do I use staircase?
Michael
October 30, 2019, 11:55pm
2
I don’t know, but probably best to start with the methodological literature before worrying about the implementation details. e.g.
TS Meese,
Perception & psychophysics , Apr 1995
In experiments that measure a point of subjective equality, it is necessary to employ a psychophysical technique that measures the 50% point (P50) on the psychometric function. The standard staircase is an attractive candidate, because its simplicity makes it easy to understand and implement. However, Pentland (1980, Perception & Psychophysics, 28, 377-379) found his own maximum likelihood method (Best PEST) to be considerably less variable than the standard staircase. Here, computer simulations were used to study the effects of manipulating several parameters of the standard staircase in order to try to find a variant that would be competitive with the performance of Best PEST. A graphical summary of some of the standard staircase implementations that were found to be most stable is presented in order that investigators may choose easily the parameters best suited to their requirements. A comparison with an implementation of Pentland's Best PEST failed to replicate Pentland's finding, suggesting that investigators should have no misgivings about the standard staircase in experiments that measure a point of subjective equality.
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