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unevenly sized lists for stimulusitems


unevenly sized lists for stimulusitems
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jdb
jdb
jdb
posted 7 Years Ago
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Posts: 6, Visits: 18
I have a question about item selection!
I have two types of trials, call them "core" and "varying" trials:
<trial core>
/ validresponse = ("1", "0")
/ correctresponse = ("1")
/ responseinterrupt = trial
/ stimulustimes = [0=noreplace(positivecore, negativecore)]
/ response = free
</trial>

<trial varying1>
/ validresponse = ("1", "0")
/ correctresponse = ("1")
/ responseinterrupt = trial
/ stimulustimes = [0=noreplace(positivevarying1, negativevarying1)]
/ response = free
</trial>

<trial varying2>
/ validresponse = ("1", "0")
/ correctresponse = ("1")
/ responseinterrupt = trial
/ stimulustimes = [0=noreplace(positivevarying2, negativevarying2)]
/ response = free
</trial>

The thing is that for each block, there should be 8 core trials for every 1 varying trial (there are 80 core items and 10 varying items). I tried using a list:
<list trials>
/items = (trial.core, trialvarying1)
/poolsize = 90
/selectionmode = random
</list>

Calling that list in a block doesn't wind up with the list doing anything – I end up with 45 core trials and 45 varying trials – not what I want. I thought about using /itemprobabilities = [.888888; .2222222] but that seems like it's not really what I mean to do. I could also potentially repeat the items in the list?
/items = (trial.core, trial.core, trial.core, trial.core, trial.core, trial.core,
     trial.core, trial.core, trialvarying1)

Anyway, I've re-ran the experiment so many times at this point that I figured I would ask for help. Anyone have a solution for this? I realize that maybe the simplest solution is to just make separate word lists (not have a core, and instead just put it in each of the other word lists) but that didn't occur to me until after I had spent a while debugging and at this point I'm feeling stubborn.
I guess I should add that I consulted this post, but haven't found it to help me find a solution.
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unevenly sized lists for stimulusitems
jdb - 7 Years Ago
     + x [quote] [b] jdb - Thursday, February 23, 2017 [/b] I...
Dave - 7 Years Ago
             + x [quote] [b] Dave - Thursday, February 23, 2017 [/b]...
jdb - 7 Years Ago

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