Conditional data.get() from specific trials

[iwe90]

Hi everyone,

I'm quite new to jspsych and I have run into a problem while coding a simple online questionnaire.

The entire structure of the questionnaire consists of if nodes, because the appearance of all following questions depends on the responses in the first survey-likert type item and/or following items.

My problem now is that I can't simply use
var data = jsPsych.data.get().last(1).values()[0];
to access the responses from the previous trials because as I understand, last() needs the exact number of previous trials (it breaks down if I put more than have been collected)- which is not possible because some people get more questions than others, depending on their responses.

Using
var first_qu = jsPsych.data.get().filter({trial: 'survey-likert'})//.values()[0];
also doesn't work for some reason and isn't helpful for the entire experiment,

neither does
var data = jsPsych.data.getDataByTimelineNode(0.0-1.0)

Can anyone suggest a different way to access the individual question responses without referring to their sequence in the data frame?

Thanks & best
Ivonne

[jodeleeuw]

Hi Ivonne,

You can use the data parameter of the trial to add a unique identifier for each question. Then you can use the .filter() method to get data from the trial that matches that identifier.

var trial = {
	type: 'survey-text',
	questions: [{prompt: 'What is your name?'}],
	data: {
		question_id: 'name'
	}
}

jsPsych.data.get().filter({question_id: 'name'})

[iwe90]

Cool, thanks for the quick reply!
I'm currently trying this and I still need the ".values()[0]" at the end, though, right?

var if_node_spr1 = { timeline: [quest_pic_spr_1], conditional_function: function() { // get the data from the previous trial, // and check which key was pressed var data = jsPsych.data.get().filter({question_id: 'quest_pic_1'}).values()[0] if(data.response.Sprachlich == '0'){ return false; } else { return true; } } } timeline.push(if_node_spr1);

[jodeleeuw]

Yes. The filter function will return the data collection and then you would need .values()[0] to get the raw data for a trial.