Millisecond Forums » Millisecond Forums » Inquisit 6 » Randomize the order of trials

Randomize the order of trials

ttyelnv — Sun, 03 Sep 2023 18:14:27 GMT

Hi Dave,

I am wondering if I can randomize the order of several trials with the list function?
In my experiment, every trial contains a movie file, as well as two markers for the movie (one for the recording with biopac, and another for the recording with eyetracker).
I have eight movie trials in total, and I'd love to randomize the order of presentation of each movie in the experiment. I also want to have a fixation cross between the transition of each movie trial.
At the moment, I have created a list attribute containing all movie trials:

<list movielist>
/items = (trial.movie1, trial.movie2, trial.movie3, trial.movie4, trial.movie5, trial.movie6, trial.movie7, trial.movie8)
/selectionmode=random
/replace = false
</list>

If I create the following block, will inquisit randomize the order of movie trials without replacement? If not, is there a way to achieve randomization in this case? I have thought about using the item attribute, but I do need the markers for each movie file. Therefore, the item attribute is not suitable in this case. Thank you in advance for your help!

<block experiment>
/trials= [1=trial.fixation; 2= list.movielist; 3= trial.fixation; 4=list.movielist; 5 = trial.fixation; 6 = list.movielist;
7=trial.fixation; 8=list.movielist; 9 = trial.fixation; 10=list.movielist; 11= trial.fixation; 12= list.movielist;
13 = trial.fixation; 14 = list.movielist; 15= trial.fixation; 16 = list.movielist]
</block>

RE: Randomize the order of trials

ttyelnv — Sun, 03 Sep 2023 18:14:27 GMT

Thank you so much Dave!

RE: Randomize the order of trials

Dave — Tue, 22 Aug 2023 17:41:05 GMT

+x[quote]

[b]nuttymenkk - 8/22/2023[/b]
Hi Dave,

I am wondering if I can randomize the order of several trials with the list function?
In my experiment, every trial contains a movie file, as well as two markers for the movie (one for the recording with biopac, and another for the recording with eyetracker).
I have eight movie trials in total, and I'd love to randomize the order of presentation of each movie in the experiment. I also want to have a fixation cross between the transition of each movie trial.
At the moment, I have created a list attribute containing all movie trials:

<list movielist>
/items = (trial.movie1, trial.movie2, trial.movie3, trial.movie4, trial.movie5, trial.movie6, trial.movie7, trial.movie8)
/selectionmode=random
/replace = false
</list>

If I create the following block, will inquisit randomize the order of movie trials without replacement? If not, is there a way to achieve randomization in this case? I have thought about using the item attribute, but I do need the markers for each movie file. Therefore, the item attribute is not suitable in this case. Thank you in advance for your help!

<block experiment>
/trials= [1=trial.fixation; 2= list.movielist; 3= trial.fixation; 4=list.movielist; 5 = trial.fixation; 6 = list.movielist;
7=trial.fixation; 8=list.movielist; 9 = trial.fixation; 10=list.movielist; 11= trial.fixation; 12= list.movielist;
13 = trial.fixation; 14 = list.movielist; 15= trial.fixation; 16 = list.movielist]
</block>
[/quote]

You can do this and it'll do what you want,but you don't even need any <list>. You can simply state your block's /trials as:

[code]<block experiment>
/ trials = [
1,3,5,7,9,11,13,15 = trial.fixation;
2,4,6,8,10,12,14,16 = noreplace(trial.movie1, trial.movie2, trial.movie3, trial.movie4, trial.movie5, trial.movie6, trial.movie7, trial.movie8);
]
</block>[/code]