Four Alternative, Forced Choice Task (case 30579)

[kmgrey]

Hello!

I should probably start by saying I am new to Direct RT.

For my experiment, I have three conditions. 8 non-words will be learned for each condition (24 non-words total). Each non-word will have an associated picture. At the end of each condition, I have a comprehension probe. I want four pictures to appear in an array. The participant will hear "Click on the ___" and they will click on one of the four images. This will repeat for all 8 non-words in this condition.

This is where I am struggling, I need the three pictures in the array, that are not the target word, to be random each time.

I am attaching my spreadsheet, as you'll see there are many missing spaces. Any help on how to create the four picture array that is random each time will be greatly appreciated!

Kim
2494

[jason_reed]

Hello Kim,

To make sure that I understand your file, can you please tell me what specific row(s) of the attached input file are supposed to be where the desired array of pictures is to appear? Also, give me an example of the specific names of the image files that you want to use in the arrays.

[kmgrey]

Rows 34-41, 83-90, and 132-139 are the row that are supposed to have the array of pictures. As you'll see also in those rows are audio stimuli, like "!clickvoogeme" that are audio clips asking the subject to click on one of the four pictures in the array.
I named the specific names of the image files as numbers so in the first group I have: 1,2,3,5,23,28,15,&17.

I am also attaching a slightly more cleaned up version of the spreadsheet.

Hope this helps!

[kmgrey]

I do not want the target word to appear in the same position in the array for each trial, I want the position to be random.

I was thinking of using: "rand(choice 1,choice 2,choice 3,.choice 4)" in the location column with the four different quadrants of the screen being the four choices. I was going to place this in each location column for the four random stimuli for that trial. Is there any way I could set this up so it is randomly selecting a location without replacement, so that I know each quadrant is covered?