By Diane - 2/21/2015
Hi,
I am using noreplace in a text element to select items from an item element that has 24 stimulus items. The text element is used by a trial element. In 2 blocks, the trial element is selected 12 times in each block. When I run the experiment, however, I find that in the first block 12 different items are selected, but in the second block about half of the 12 items overlap with those in the first block. Thus, the randomization seems to be reset between blocks. How can I prevent this from happening?
Thanks,
Diane
Examples of the block, trial, and text elements:
<block RPblock1>
/trials = [1-96 = noreplace(repeatHF, repeatLF, nonrepeatHF, nonrepeatLF, repeatNW, repeatNW, nonrepeatNW, nonrepeatNW)]
/postinstructions = (breakRP)
</block>
<block RPblock2>
/trials = [1-96 = noreplace(repeatHF, repeatLF, nonrepeatHF, nonrepeatLF, repeatNW, repeatNW, nonrepeatNW, nonrepeatNW);97 = totaltime]
</block>
<trial repeatHF>
/stimulustimes =[0=RPfixation;450=RPblank;500=repeatedHF]
/ validresponse = (30,38)
/ correctresponse = (38)
/errormessage = true(RPerrortext, 1000)
/ branch = [if (trial.repeatHF.latency > 1500) trial.slowfeedback]
/posttrialpause = 1000
</trial>
<text repeatedHF>
/ items = repeatedHFwords
/ fontstyle = ("Verdana", 3.00%)
/select = noreplace
</text>
<itemrepeatedHFwords>
/1 = "soul"
/2 = "army"
/3 = "strong"
/4 = "floor"
/5 = "table"
/6 = "drop"
/7 = "control"
/8 = "company"
/9 = "touch"
/10 = "shoot"
/11 = "full"
/12 = "reason"
/13 = "fight"
/14 = "sleep"
/15 = "police"
/16 = "part"
/17 = "under"
/18 = "since"
/19 = "open"
/20 = "excuse"
/21 = "matter"
/22 = "believe"
/23 = "after"
/24 = "maybe"
</item>
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By Dave - 2/21/2015
> Thus, the randomization seems to be reset between blocks.
Yes, that's what is supposed to happen by default. To override this behavior, use the stimulus element's /resetinterval attribute.
<text sometext>
...
/ resetinterval = 0
</text>
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