Go around the loop's unsupported features

S_H

Dear OS community,

I have an experiment that I wish to run online.

The procedure of preparing the stimuli is comprised of a chain of loops in which each property of the stimuli is chosen in a designated loop. After going through the chain, the stimuli is presented and a new set of properties are chosen from those who weren't polled in the previous trial. These steps were taken in order to randomize properties between trials and make sure that there is no property that is shown in an unbalanced way. Please find an example attached. 

Practically, it means that most of the loops are defined as "Break if: always" and the "Resume after break" is checked. This definitions are not supported in OSWeb.

Can anyone recommend me way (e.g., code in JS, structural changes) to go around those definitions that will eventually allow me to randomize several properties without replacement?

Thanks in advanced!!!

SH

Example.osexp

eduard

Hi Stephen,

Couldn't you prepare the schedule offline before the experiment starts and then just load the loop table from a csv/excel file? I am not sure whether I understand the motivation behind your example script correctly, but from what I see in the example file you attached, this should be possible, by prespecifying which color/size combinations to show (and in which order).

Alternatively you would have to work with list-like structures in javascript, and then carry this loop table through your experiment. If not terribly complicated, that could also be a viable solution.

Eduard

S_H

Thank you very much for your answer Eduard!

I'm very interested in the alternative that you suggested.

The thing is that, as written here:

"The JavaScript workspace is not persistent. That is, if you define a variable in one script, it will not be accessible in another script. Exceptions are the vars object and other variables that are globally available in JavaScript (e.g. window)."

Will it be possible to create a "vars" list and to access a part of it in another code and then in a canvas?

I will illustrate an example.

In the beginning of the script to create the list:

 list = [
    { Color1: 'blue', Color2: 'green'},
    { Color1: 'green', Color2: 'yellow'},
    { Color1: 'yellow', Color2: 'red'}
];

vars.list = shuffle(list) // shuffle function will be created sepereatly 

and prior to the trial to do something like:

Number = vars.count_Seq // In order to get a consecutive number

vars.Color1Now = alert(vars.list[NUMBER].Color1); //define the trials first stimuli's color
vars.Color2Now = alert(vars.list[NUMBER].Color2); //define the trials second stimuli's color

and within the sketchpad to define the color "[Color1Now]"

Will that work?

eduard

Hi Stephen,

Generally, this should be possible. I don't know enough about js to check your syntax. Better just try it out yourself.

Small note: Most shuffle functions don't return a shuffled object, but only None. So first shuffle, and once you shuffled assign the shuffled list to vars.list

Good luck!

Eduard

S_H

Thank you so much!

Daniel

Small note: Most shuffle functions don't return a shuffled object, but only None. So first shuffle, and once you shuffled assign the shuffled list to vars.list

Actually, in Javascript there is no native shuffle function 😮. I usually revert to lodash for these functions that should have been in the standard library, but it is hard to use this library in osweb script items.

Here are some examples of how to implement a shuffle function in pure javascript: https://medium.com/@nitinpatel_20236/how-to-shuffle-correctly-shuffle-an-array-in-javascript-15ea3f84bfb which you could copy-paste

S_H

Thanks Daniel!

Daniel

I also recently discovered pythonic, which brings a lot of common python functions to javascript with similar signatures.

Also, have a read through https://dev.to/massa142/javascript-is-almost-pythonic-3f8 to see how python and javascript have become very similar.