Hi there,
I'm programming a task that people rate two images on how similar they are. I have 8 images in total and if people rate image 1 with image 1, image 1 with image 2, image 1 with image 3.. etc. it would be 36 times of rating in total if each image is compared with all other images and itself. But I cant figure out how I can make people only rate each pair only once without repeats. Is there a command that I can use for that?
Here is my script.
<data>
/ separatefiles = true
/ columns = [build, computer.platform, date, time, subject, group, blockcode, blocknum,
trialcode, values.trialnum, stimulusitem, values.left_alien, values.right_alien
response, latency]
</data>
<summarydata>
/columns = (script.filename,script.startdate, script.starttime,
script.subjectid, script.groupid, script.elapsedtime, computer.platform,
values.completed, values.attentioncheck_correct)
/ separatefiles = true
</summarydata>
<item images>
/1 = "A1.jpg"
/2 = "A2.jpg"
/3 = "A3.jpg"
/4 = "A4.jpg"
/5 = "A5.jpg"
/6 = "A6.jpg"
/7 = "A7.jpg"
/8 = "A8.jpg"
</item>
<values>
/response = 0
/trialnum = 0
/attentioncheck_correct = 0
/completed = 0
/left_alien = ""
/right_alien = ""
</values>
<picture left_images>
/ items = images
/ position = (30, 50)
/ select = noreplacenorepeat
</picture>
<picture right_images>
/ items = images
/ position = (70, 50)
/ select = noreplacenorepeat
</picture>
<picture scale>
/ items = ("scale.jpg")
/ size = (50%, 50%)
/ position = (50, 80)
</picture>
<text instructions>
/items= ("
In this task, you are asked to rate how similar
two alien images are on a scale from 1 to 4,
with 1 indicating extremely dissimilar to 4 extremely similar.
Use the number keys (1, 2, 3, 4) to respond.
Please press the spacebar to continue.")
</text>
<text attentioncheck>
/items = ("
This is an attention check question.
Please press 'f' on your keyboard.
")
/ position = (50, 70)
/ fontstyle =("Helvetica", 2.5%, false, false, false, false, 5, 0)
</text>
<text end>
/items = ("
Thanks for participating!
Please press the space bar to exit.")
</text>
<trial instructions>
/ stimulusframes = [1 = instructions]
/ validresponse = (57)
/ recorddata = false
</trial>
<trial end>
/ stimulusframes = [1 = end]
/ validresponse = (57)
/ recorddata = false
</trial>
<trial rating>
/ ontrialbegin = [values.left_alien= picture.left_images.currentitem;
values.right_alien = picture.right_images.currentitem]
/ stimulusframes = [1=picture.scale, picture.right_images, picture.left_images]
/ validresponse = (2, 3, 4, 5)
/ ontrialend = [values.trialnum = values.trialnum + 1]
</trial>
<trial attentioncheck>
/ stimulusframes = [1=attentioncheck, picture.scale, picture.right_images, picture.left_images]
/ validresponse = (2, 3, 4, 5, 33)
/ ontrialend = [if (trial.attentioncheck.response == 33) {values.attentioncheck_correct = 1}]
</trial>
<block rating>
/trials = [1=instructions; 2-18=rating; 19=attentioncheck; 20-38 = rating; 39 = end]
</block>
<expt >
/ blocks = [1=rating]
/ onexptend = [values.completed = 1]
</expt >