[visionlist] [EXTERN] Re: Forced Choice – please educate me

[Michael Bach]

Dear Erik:

Thank you!

> (Just quickly before we get into the weeds, I think you were just speaking offhandedly, but I think the left/right and landolt C examples are not nAFC, but “identification” tasks. For the motion direction example, you’d need two stimuli in two places (or two intervals) and then ask e.g., “which went left?”. For a landolt 8AFC, you’d need 8 landolts, and ask e.g., “Which one has the gap in the upper left?” I think it’s best to think of the n in nAFC as the number of stimuli, not response choices. This would all be less confusing if nIFC were more common than nAFC!)

hmm, here I beg to differ: _Identification_ of 8 choices is also an 8AFC methinks (as long as they are “equivalent”, that is differ in only one parameter {as Marc Ernst pointed out to me}).


Thanks & best, Michael
-- 
https://michaelbach.de