Stroop Test

One of the activities you can add to your study is the Stroop test. A Stroop test offers configurations that are similar to other Ethica activities. If you have not read about using Activities in an Ethica study, we encourage you to start from there first.

Similar to surveys, a Stroop test can also have one or more Triggering Logics. They define when and how often the participant should complete the Stroop activity. Unlike surveys, Stroop activities cannot contain Eligibility or Dropout triggering logic. You can only use Time, User, or Proximity Triggering Logics with the Stroop activity.

Every time Ethica prompts a Stroop activity to the participant, regardless of what kind of triggering logic caused that prompt, a new Session is created for it. This Stroop session stores all data related to the test. The session may have an expiry time. In this case, the participant has a certain amount of time to complete the Stroop activity before its session is marked as Expired.

Stroop activities can have a Notification as well, to notify participants about completing the activity. All settings we explained in the Activity Notifications can be used for creating notifications for your Stroop activity as well.

Also, Stroop activities, their triggering logics, and their notifications can have a criteria. In this case, the activity or the Triggering Logic or the Notification is only enabled if the criteria is evaluated to True. You can read more about Criteria here. Note that although you can assign a criteria to a Stroop test, the criteria can only use survey questions for the evaluation. You cannot use the data from a Stroop session in your criteria. For example, it's not possible to create a criteria that says "prompt this activity only if the Stroop session was completed".

Supported Stimuli

The Stroop test supports three types of stimuli:

  • Congruent refers to the case where the text is the same color as the font color.
  • Incongruent refers to the case where the text is a different color from the font color.
  • Neutral refers to the case where the text shown on the screen does not represent any color.
Congruent Stimulus Incongruent Stimulus Neutral Stimulus
Congruent Stimulus Incongruent Stimulus Neutral Stimulus

Add a New Stroop Activity

To create a new Stroop activity, open the Researcher Dashboard and navigate to the Activities page. Click on the New button and from the list, choose Stroop.

This will open the Stroop Activity Editor. If you already have created surveys or other activity types, you should be familiar with most of the options available in this activity editor. For example, the Triggering Logic section allows you to configure the activity's triggering logics, or the Notification section allows you to create notifications and reminders for your activity. Below we focus on the Content section and explain the settings that are listed there.

General Settings

In this section, you can set the flow of the game, the length of it, and the type of stimuli it should include:

General Settings of the Stroop Activity
Editor

The first setting, Duration Type, specifies whether the game should be finished after a certain time (Time), or a certain number of rounds (Round). If you choose Time, you need to specify how long each game should be, in seconds. If you choose Round, you need to specify how many rounds each game should have.

You can set the Tutorial Round Count to specify how many tutorial rounds the game should have. Each session of the game starts with the tutorial. The participant must complete the tutorial before starting the main game.

In the last part of the General Settings, you specify what type of stimuli you want to include in the game. You can choose from congruent, incongruent, and neutral rounds. If your game is time-based, you can include or exclude either of these stimuli. Ethica randomly generates enough rounds to fill the game duration.

If your game is round-based, you can let Ethica randomly generate enough rounds of each stimulus, such that it adds up to the number of rounds you have specified. You can also enter manually how many rounds of each stimulus you would like to have. In this case, Ethica guarantees that each session of the game will contain that many stimulus, and presents them randomly.

For example, you can specify your game is round-based, and each participant should complete 30 rounds of the game. Then you can set that each session of the game should contain 12 congruent rounds, 12 incongruent rounds, and 6 neutral rounds. This way, for each session of the game, Ethica will generate the round types as specified (12-12-6), and presents them randomly to the participant.

Game Messages

Throughout the game, Ethica shows 3 messages to the participant. You can modify these messages and their translation in this section:

Game Messages Settings of the Stroop Activity
Editor

The Game Introduction Message is shown on the first screen of the game, immediately after the participant opens the game. This is the message they see first when they start a session of this activity. This text cannot be longer than 500 characters.

Following the introduction page, the participant is taken to the tutorial rounds. When they complete the tutorial rounds and before they start the main game, they are shown the Pre-game Message. This text cannot be longer than 500 characters either.

The Text for Neutral Rounds, as it's name implies, specifies the text that should be used for the neutral stimulus rounds. In the congruent or incongruent rounds, Ethica shows the color names. But for the neutral rounds you can type a set of characters and that will be shown in each neutral rounds. Note that this does not have to be a readable text. For example, you can set this to ##### and Ethica will show this for each neutral round. This text cannot be longer than 10 characters.

Game Layout

The last set of settings in this section allows you to configure the layout of the game user interface:

Game Layout Settings of the Stroop Activity
Editor

The first option, Selector Layout, allows you to choose how the choices should be shown to the participant. If you set the Selector Layout to Yes/No, the participant is asked whether the two colors are identical or not, and they should respond by choosing Yes or No in the game.

Congruent Stimulus with Yes/No Selector Incongruent Stimulus with Yes/No Selector Neutral Stimulus with Yes/No Selector
Congruent Stimulus with Yes/No Selector Incongruent Stimulus with Yes/No Selector Neutral Stimulus with Yes/No Selector

If you set the Selector Layout to Color Box, the participant is shown a colored text, and is asked to tap on the box with a similar color.

Congruent Stimulus with Color-Box Selector Incongruent Stimulus with Color-Box Selector Neutral Stimulus with Color-Box Selector
Congruent Stimulus with Color-Box Selector Incongruent Stimulus with Color-Box Selector Neutral Stimulus with Color-Box Selector

If you set the Selector Layout to Color Name, the participant is shown a colored text and is asked to tap on the name of the color they see.

Congruent Stimulus with Color-Name Selector Incongruent Stimulus with Color-Name Selector Neutral Stimulus with Color-Name Selector
Congruent Stimulus with Color-Name Selector Incongruent Stimulus with Color-Name Selector Neutral Stimulus with Color-Name Selector

The next option allows you to pick what colors should be part of the game. You can choose any combination of the colors that is available.

The Audio Feedback and Visual Feedback options control whether or not the game should provide audio and visual feedback to the participant when they correctly or incorrectly respond to each round.

The Show Round for round-based games, and Show Timer for time-based games, specify whether the timer or round counter should be shown in the game interface or not.

Lastly, the Show Score option controls whether the game should show the participants how many correct answers they have provided.

Stroop Response Data Structure

You can download the responses for your Stroop activity either as a CSV file, or you can view them in the Kibana integration of the dashboard. Either way, each record of the data contains the following attributes:

Name Field Name Type Description
Study ID study_id Integer The ID of the study for which this record belongs to.
Participant ID user_id Integer The ID of the participant who submitted this response.
Activity ID activity_id Integer The ID of the Stroop activity which this record belongs to.
Session UUID session_uuid Text (UUID) The unique identifier of the Stroop session which this record belongs to.
Device ID device_id Keyword The ID of the device on which the participant completed this Stroop session.
Triggering Logic ID tl_id Integer The ID of the Triggering Logic which prompted this Stroop session.
Triggering Logic Type tl_type Text The type of the Triggering Logic which prompted this Stroop session.
Scheduled Time scheduled_time Date For Time- and Proximity-Triggered sessions, this shows the time the Stroop activity was automatically triggered. For User Triggered sessions, this shows the time the Stroop activity was started by the participant.
Prompt Time prompt_time Date Same as Scheduled Time.
Record Time record_time Date The time the Stroop activity was completed by the participant.
Relative Record Time rel_record_time Date The number of milliseconds between the participant's participation start time, and the time this session was completed.
Session Status status Integer The status of the session. More here
Maximum Colored Box max_colored_box Integer Shows the maximum number of rounds that were presented during this game session.
Maximum Colored Text max_colored_text Integer Always the same as max_colored_box
Round Index round_index Integer The index of the round that this response belongs to.
Response Time resp_time Date The time that this response was provided.
Box Font Color box_font_color Text The color of the ink that was used to write the text.
Text Color text_color Text The color that the text represented. For example, if the text is "Red", the text_color will be red. This will be Unknown for neutral rounds, as the text does not represent any color.
Question Color question_color Text If the selector type is Yes/No, this represents the color text asked from participants. For Colored Box and Colored Text selectors, this value is always not defined (equals to Unknown).
Response response Integer If the selector type is YES/NO, the value is 0 for No and 1 for Yes. If the selector type is Colored Box or Colored Text, the value is the ID of the selected color, as defined in the Color IDs below.
Response Duration response_duration Integer The duration it took for the participant to submit this response. This value is calculated by subtracting the resp_time for this round index from resp_time for the round index before this record.

Color IDs

Color Name ID
Unknown 0
Blue 1
Yellow 2
Red 3
Green 4
Black 5

Selector Type IDs

Selector Type ID
Colored Box 1
Colored Text 2
Yes/No 3

Game Duration Type IDs

Duration Type ID
Timed 1
Round 2