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Group: Forum Members
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Hello, I have 3 categories of stimuli, containing 5 stimuli each (so, there is a total of 15 stimuli). I want to run 24 trials total, but I do NOT want each category to be presented at equal frequency or ratios. I want the ratio of the stimuli from the three cateorgies to go in this breakdown 7:7:10. How do I do that? In other words, I want to assign a frequency to each category, but then have Inquisit select them at random? They syntax I thought might work is: /trials=random[1-7=noreplace(category1);8-14=noreplace(category2);15-24=noreplace(category3)] However, this does not tell Inquisit to select all the trials randomly because it defines trials 1 through 7 from category1 and trials 8-14 from category 2, etc. I just basically want to tell Inquisit the ratio: category1 should have 7 trials, category2 should have 7 trials, and category3 should have 10 trials (and select the trials in random order following this category ratio). Any suggestions would be greatly appreciated! Thanks!
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Group: Administrators
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To sample trials in the desired proportions (7:7:10), you must simply enter them to the noreplace selection pool in the desired proportions. In your case that's <block myblock>
/ trials = [1-24=noreplace(
category1,category1,category1,category1,category1,category1,category1,
category2,category2,category2,category2,category2,category2,category2,
category3,category3,category3,category3,category3,category3,category3,
category3,category3,category3)
]
[...]
</block> Regards, ~Dave
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Group: Forum Members
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Visits: 1
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Thank you Dave, that was quite helpful!! -Valerie
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Group: Forum Members
Posts: 12,
Visits: 64
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Hi,
To add to this question I was wondering if it is possible to manipulate the randomised selection so that no two same stimuli are selected in a row. Is it possible to do this? If so, how would that be established?
For example: I have digits 1-9 selected from a list presented 24 times but I want the selection order to be randomised each time and ensure the same digit is not represented twice. Would a no replace function work in this instance?
/items = (
trial.practice_go, trial.practice_go, trial.practice_go, trial.practice_go, trial.practice_nogo, trial.practice_go, trial.practice_go, trial.practice_go, trial.practice_go, trial.practice_go, trial.practice_go, trial.practice_go,
trial.go, trial.practice_go, trial.practice_go, trial.practice_nogo, trial.practice_go, trial.practice_go, trial.practice_nogo, trial.practice_nogo, trial.practice_go, trial.practice_nogo, trial.practice_go, trial.practice_go)
/ replace = false
</list>
Note: list of digits used for practice; tied to list.practice_trialtypes
<list practice_digitsequence>
/items = (
1, 2, 8, 4, 2, 3, 1, 5, 6, 7, 3, 4, 1, 2, 3, 9, 3, 2, 7, 9, 5, 4, 2, 5)
/selectionmode = list.practice_trialtype.currentindex
/resetinterval = 1
</list>
<block practice>
/postinstructions = (practiceend MWexamples1 realtask)
/trials = [1 = getReadyPrac; 2-25 = list.practice_trialtype]
/onblockend = [list.fontsizes.reset()]
</block>
Apologies if my question is not understandable. Any help would be greatly appreciated.
Thanks.
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Group: Administrators
Posts: 12K,
Visits: 98K
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+xHi, To add to this question I was wondering if it is possible to manipulate the randomised selection so that no two same stimuli are selected in a row. Is it possible to do this? If so, how would that be established? For example: I have digits 1-9 selected from a list presented 24 times but I want the selection order to be randomised each time and ensure the same digit is not represented twice. Would a no replace function work in this instance? /items = ( trial.practice_go, trial.practice_go, trial.practice_go, trial.practice_go, trial.practice_nogo, trial.practice_go, trial.practice_go, trial.practice_go, trial.practice_go, trial.practice_go, trial.practice_go, trial.practice_go, trial.go, trial.practice_go, trial.practice_go, trial.practice_nogo, trial.practice_go, trial.practice_go, trial.practice_nogo, trial.practice_nogo, trial.practice_go, trial.practice_nogo, trial.practice_go, trial.practice_go) / replace = false </list> Note: list of digits used for practice; tied to list.practice_trialtypes <list practice_digitsequence> /items = ( 1, 2, 8, 4, 2, 3, 1, 5, 6, 7, 3, 4, 1, 2, 3, 9, 3, 2, 7, 9, 5, 4, 2, 5) /selectionmode = list.practice_trialtype.currentindex /resetinterval = 1 </list> <block practice> /postinstructions = (practiceend MWexamples1 realtask) /trials = [1 = getReadyPrac; 2-25 = list.practice_trialtype] /onblockend = [list.fontsizes.reset()] </block> Apologies if my question is not understandable. Any help would be greatly appreciated. Thanks. > I have digits 1-9 selected from a list presented 24 times but I want the selection order to be randomised each time and ensure the same digit is not represented twice. Would a no replace function work in this instance? No, since your digit list's selection is dependent on the selection in the trial type list. Note: list of digits used for practice; tied to list.practice_trialtypes<list practice_digitsequence> /items = ( 1, 2, 8, 4, 2, 3, 1, 5, 6, 7, 3, 4, 1, 2, 3, 9, 3, 2, 7, 9, 5, 4, 2, 5) /selectionmode = list.practice_trialtype.currentindex/resetinterval = 1 </list>
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