Millisecond Forums » Millisecond Forums » Inquisit 5 » Random trial selection with branching

Random trial selection with branching

EstherKlinkenberg — Wed, 19 Dec 2018 03:29:53 GMT

Dear all,

I'm struggling to create an experiment in which Inquisit randomly selects one of my three trial types. I've got multiple trials differing in how fast a stimulus will be presented after the mouse click of a participant. I would like to add a condition in which the trials are selected randomly.

my branching code:

/ branch = [if (trial.1to4arrow_direct_500.response == "player4label") trial.1to3arrow_direct_500_excluded]
/ branch = [if (trial.1to4arrow_direct_500.response == 0) trial.1to4_direct_500]

In both the trial.1to3arrow_direct_500_excluded and the trial.1to4_direct_500 the "500" stands for the ms it takes for a stimulus to appear. I created two other conditions in which the ms are 1000 and 1500. I would like to create a condition in which inquisit randomly selects the 500, 1000 or 1500 ms trial. I started making a <list> element with all the trials, however, now I am not sure how to tell inquisit to randomly select a trial from that list (including the if statements for the responses).

I hope this makes sense, if not, I could try explaining it with my whole code but since it is quite elaborate I hope this is clear enough.

Thank you in advance for helping!

Kind regards,
Esther

RE: Random trial selection with branching

EstherKlinkenberg — Wed, 19 Dec 2018 03:29:53 GMT

[quote]

[b]Dave - Monday, December 17, 2018[/b]

[quote]

[b]EstherKlinkenberg - Monday, December 17, 2018[/b]

[/quote]

Suposse you have three <trial> elements a, b and c. You want ten each, and /branch to them randomly. Then you do

<list triallist>
/ items = (trial.a, trial.b, trial.c)
/ poolsize = 30
/ selectionmode = random
/ replace = false
</list>

with

<trial example>
...
/ branch = [if (true) list.triallist.nextvalue]
</trial>

[/quote]

Thanks!!

RE: Random trial selection with branching

Dave — Mon, 17 Dec 2018 07:20:21 GMT

[quote]

[b]EstherKlinkenberg - Monday, December 17, 2018[/b]

[/quote]

Suppose you have three <trial> elements a, b and c. You want ten each, and /branch to them randomly. Then you do

<list triallist>
/ items = (trial.a, trial.b, trial.c)
/ poolsize = 30
/ selectionmode = random
/ replace = false
</list>

with

<trial example>
...
/ branch = [if (true) list.triallist.nextvalue]
</trial>