random w/o replacement is still replacing

[Diana]

Hi all, 

I have a memory task that displays a series of images in different locations on the screen. The participant is expected to remember the image and its location, so when the images are pulled randomly from a nested list, the participant can match the image to the original location. 

The problem I am encountering involves the random pulling of images to be matched. I need this to happen without replacement, but even with the selection order set to 'random', I'm having at least one image being pulled twice and one image not pulled at all. 

I have no idea how to fix this problem. Is there anyone that can share some insight?

 

Thanks for the time,

Dazed & Confused (Diana)

[David Vinson]

Hi Diana,

one possibility is that ResetList is set to a value lower than the
number of items on the list that you want to sample. If so it will
sample without replacement until it reaches the value specified by
ResetList at which point it will start over from the full list. This
could produce the problem you describe.

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