jsPsych/docs/markdown_docs/plugins/jspsych-survey-likert.md

jspsych-survey-likert plugin

The survey-likert plugin displays a set of questions with Likert scale responses. The subject responds by selecting a radio button.

Parameters

This table lists the parameters associated with this plugin. Parameters with a default value of undefined must be specified. Other parameters can be left unspecified if the default value is acceptable.

Parameter	Type	Default Value	Description
questions	array	undefined	Each array element a string. The strings are the prompts/questions that will be associated with a slider.
labels	array	undefined	Each array element is an array of strings. The innermost arrays contain a set of labels to display for an individual question. If you want to use blank responses and only label the end points or some subset of the options, just insert a blank string for the unlabeled responses.

Data Generated

In addition to the default data collected by all plugins, this plugin collects the following data for each trial.

Name	Type	Value
responses	JSON string	A string in JSON format containing the responses for each question. The encoded object will have a separate variable for the response to each question, with the first question in the trial being recorded in Q0, the second in Q1, and so on. The responses are recorded as integers, representing the position of the slider on the scale.
rt	numeric	The response time in milliseconds for the subject to make a response. The time is measured from when the questions first appear on the screen until the subject's response.

Examples

Basic example with multiple questions on a page.

// defining groups of questions that will go together.
var page_1_questions = ["I like vegetables.", "I hate eggs."];

// defining two different response scales that can be used.
var scale_1 = ["Strongly Disagree", "Disagree", "Neutral", "Agree", "Strongly Agree"];

var likert_page = {
    type: 'survey-likert',
    questions: ["I like vegetables.", "I like fruit."],
    labels: [scale_1, scale_1], // need one scale for every question on a page
};