Conditional end of experiment

[filippoferrari]

Hi,

I have an experiment to run on Prolific with a first section of questionnaires and later a behavioural task.
I want to end the experiment after the questionnaire section if a certain numbers of attention checks are failed, but still upload the data collected so far to my database (so I can check the failed attention checks and pay the participans accordingly) and redirect the user back to Prolific.

My code structure is as follows.

// Set up
    var jsPsych = initJsPsych({
        show_progress_bar: true,
        auto_update_progress_bar: false,
        message_progress_bar: 'Section Progress',
        override_safe_mode: true,
        on_finish: function () {
            // window.location = "https://app.prolific.co/submissions/XXXXXXX" // commented out for testing
            window.location = "https://google.com"
        }
    });
    const timeline = [];

// Intro trials - not shown
// Questionnaire trials - not shown

// Attention checks 
    var failed_attention_checks_end = {
        type: jsPsychHtmlButtonResponse,
        choices: ["Continue"],
        stimulus: `<p>Sorry, you've failed the attention checks so the experiment will now end.</p> 
        <p>If something went wrong that explains why the attention checks were not completed, please contact the researchers through the Prolific messaging system.</p>
                   <p>Click 'Continue' to be redirected to Prolific.</p>`,
        on_finish: function(data) {
            jsPsych.endExperiment();
        }
    }

    var if_attention_checks = {
        timeline: [failed_attention_checks_end],
        conditional_function: function(){
            // if participant failed 2 or more attention checks end the experiment
            var data = jsPsych.data.get().filterCustom(function(x){ return x.trial_type == 'survey-template' && x.failed_attention_checks > 0 });;
            if(data.count() >= 2){
                return true;
            } else {
                return false;
            }
        }
    }

    timeline.push(if_attention_checks)

// Rest of experiment - not shown

// Upload data to database
    var upload_data_trial = {
        type: jsPsychCallFunction,
        async: true,
        func: function (done) {
            const experimentalData = jsPsych.data.get().json();
            const xhr = new XMLHttpRequest();
            xhr.open('POST', `write_data.php?pid=${subject_id}`);
            xhr.setRequestHeader('Content-Type', 'application/json');
            xhr.onload = () => {
                if (xhr.status === 200) {
                    const response = xhr.responseText;
                    console.log(response);
                } else {
                    console.log("Couldn't connect to `write_data.php`");
                }
                done();
            };
            xhr.send(experimentalData);
        }
    }

    var end = {
        type: jsPsychHtmlButtonResponse,
        on_start: function () {
            jsPsych.setProgressBar(1);
        },
        stimulus: `<p>Thank you for taking part in the experiment!</p>
                   <p>You can now close your window!</p>`,
        choices: ["Bye!"]
    };
 
    timeline.push(upload_data_trial);
    timeline.push(end);

    // Run experiment
    jsPsych.run(timeline);

My question is, how can I call my upload_data_trial trial as part of the if_attention_checks node and then have the user redirected to prolific?

I have tried var if_attention_checks = { timeline: [upload_data_trial , failed_attention_checks_end], etc} but it results in the following console error [Error] Trial level node is missing the "type" parameter. The parameters for the node are: {}.

Any help would be greatly appreciated!

[jodeleeuw]

I have tried var if_attention_checks = { timeline: [upload_data_trial , failed_attention_checks_end], etc} but it results in the following console error [Error] Trial level node is missing the "type" parameter. The parameters for the node are: {}.

This seems like the right approach to me. Was the upload_data_trial variable defined before the if_attention_checks one in the script?

[filippoferrari]

That was it! Thank you so much :)