Millisecond Forums

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!

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