What is the easiest way to capture participant ID from a url and save to the .csv?

[Cluster-Bomb]

Hi there,

Need to capture the participant ID from the experiment url and somehow save it to the .csv along with all the other trial data.

I have no problem capturing the ID using jsPsych.data.getURLVariable(var_name) - however I dont know how to write it to the .csv.

Cheers

[jodeleeuw]

jsPsych.data.addProperties() will do what you are looking for.

var subject_id = jsPsych.data.getURLVariable('PROLIFIC_PID');
jsPsych.data.addProperties({
	subject_id: subject_id
});

[kupiqu]

I think I understand what's going on now:

• if I use jsPsych.data.addProperties instead of jsPsych.data.write above, it adds the prolific information to all lines in the csv file, and there's only one prolific_info line.

• if I use the "write" version as it is above, there's two lines for prolific_info because there is one additional line that is written automatically at the end of the trial, which is empty because the properties have not been added anywhere.

I sort of like the second minimalistic option better so the prolific info is not spread all around but it just appears in its line. However, I'd like to prevent the appearance of the second empty prolific_info line.

@jodeleeuw, is there a way to disable the automatic jsPsych.data.write call at the end of a trial?

[jodeleeuw]

No, you can't disable the data.write call because jsPsych makes the assumption that every plugin call gets associated with one entry in the data array. But the return value of the function in call-function is stored in the data, so you could add it by returning it from the function.

One reason to have the prolific id on every line of the data file is it keeps the data tidy. This makes it easy to interface with data analysis tools like R's tidyverse that expect tidy data. But obviously if your analysis doesn't require that then you can save a little space in the data by having the ID appear once. I just wanted to mention this here for others who are viewing this thread and wondering which approach to use.

[kupiqu]

Thanks @jodeleeuw for the clarification!

But the return value of the function in call-function is stored in the data, so you could add it by returning it from the function.

Unfortunately the value returned by jsPsych.data.urlVariables() is [object Object]

One reason to have the prolific id on every line of the data file is it keeps the data tidy.

I do use R (in fact I use jaysire to build the experiment) and I would appreciate this feature to simplify my analysis. However, in my case, I still need to do some parsing as I want my analysis scripts to deal with two types of participants: online participants via Pavlovia-Prolific; and "local" participants performing the experiment in the lab.

For the latter, I ask participants to manually enter their own participant id using the jspsych-survey-text plugin and so far I couldn't find a way (in jaysire) to set the content of responses in a new column named participant_id.

I guess this would require porting jsPsych.data.addProperties to jaysire.

EDIT: insert_property can be used for adding jsPsych.data.addProperties in jaysire, however the problem is how to introduce a jsPsych variable in it

[jodeleeuw]

I haven't got too much experience with jaysire yet, but if you can hook into the on_finish event for the text entry trial, you can do something like this:

var trial = {
	type: 'survey-text',
	on_finish: function(data){
		var id = JSON.parse(data.responses).Q0;
		jsPsych.data.addProperties({subject_id: id})
	}
}

[kupiqu]

I adapted your response to my case as follows and worked!

    on_finish = insert_javascript(
      "function(data){
        var id = JSON.parse(data.responses).participant_id;
        jsPsych.data.addProperties({participant_id: id})
      }"
    )

This is actually great for my analysis, and a very nice know-how, thanks!!

[Cluster-Bomb]

Thanks - works great!