Sampling with fixed repetitions - randomisation not working

[fin329]

Hey everyone,

I'm currently trying to randomise my trials with the sampling methods given on jspsych.org. I'm using the fixed repetitions option. It should repeat every trial 3 times, but in a random order. Currently the repetition is working, but it repeats the trials in order (see shortened in- & output below). The trials are variables defined before. I tried to set randomize_order to true, but that didn't change a thing.

Probably an easy one, but I could not find a solution by now. Any hint would be appreciated! :)
Also: Is there any option to use the fixed repetitions with unequal probabilities? Adding "weights" is not working with this one.

var timeline_test_random = {
timeline: [trial1, trial2, trial3, trial1_2, trial2_2, trial3_2],
sample: {
type:'fixed-repetitions',
size: 3
}
}

Output:
trial1, trial2, trial3, trial1_2, trial2_2, trial3_2, trial1, trial2, trial3, trial1_2, trial2_2, trial3_2, trial1, trial2, trial3, trial1_2, trial2_2, trial3_2

[jodeleeuw]

Hi @fin329,

The sample parameter (and randomize_order) only applies to the timeline variables, not the timeline itself. The motivation for this is that the timeline represents the fixed procedure that runs (e.g., show a fixation cross, show a stimulus, show feedback) and the timeline variables represent what is different between trials. This is why you are getting the same order each time.

[fin329]

Thanks a lot, didn't realize that! :)