Millisecond Forums » Millisecond Forums » Inquisit 2.0 » Randomize trials that have already been defined

Randomize trials that have already been defined

Valerie — Tue, 02 Jun 2020 23:35:19 GMT

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!

RE: Randomize trials that have already been defined

Dave — Tue, 02 Jun 2020 23:35:19 GMT

+x[quote]

[b]aliciay1 - 5/29/2020[/b]
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.
[/quote]

> 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>

RE: Randomize trials that have already been defined

aliciay1 — Fri, 29 May 2020 01:59:01 GMT

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.

RE: Randomize trials that have already been defined

Valerie — Wed, 13 Oct 2010 06:50:13 GMT

Thank you Dave, that was quite helpful!!

-Valerie

RE: Randomize trials that have already been defined

Dave — Fri, 08 Oct 2010 13:06:52 GMT

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