2 Launch a Study

We developed the DICE web-app for researchers to launch a study without any coding and without hosting the oTree app yourself. This section guides you through the process step by step.

2.1 Meta Information

We ask you to provide some information about yourself and the study you intend to run. The DICE app uses these information to provide participants with contact information if any questions occur. In addition, the DICE app displays an external study name. The internal name only serves internal documentation purposes for yourself.

2.2 Participant Recruitment

As of today, we optimized the DICE app for Prolific. However, the DICE app can also create generic URLs that can be used for any other recruitment platform or strategy. In any case, you need to specify the number of rows in a database that will be created specifically for your study. Each row can be assumed by one participant. If there is attrition, that is, if a participant enters the study but leaves before finishing it, his or her row in the database will be taken and cannot be overwritten by other participants. Hence, you should consider attrition while specifying the number of rows in the database as participants who try to enter the experiment after all slots (rows in the database) are used, will receive an error message.

Whereas it is costly for you to underestimate attrition, it is also costly for you (and us) to overestimate attrition and enter an unreasonably large number of desired rows because this can have implications on the performance. For this reason, we enforce a maximum of 400 rows here. Feel free to contact us, if you require larger sample sizes and we’ll schedule a session together. Or consider deploying a Digital In-Context Experiment yourself.

2.3 Stimulus Design

2.3.2 URL

In this section, you will provide the csv file you created to configure your stimuli as described in Chapter 1. The DICE app “ingests” these configurations if you provide raw URL to the file. This requires you to upload the csv file in a publicly available storage (we recommend GitHub as it is free and easy-to-use).

The DICE app needs access to your CSV file through what’s called a “raw” URL. A raw URL points directly to the file’s content, allowing DICE to read your configuration. Think of it as a direct link to the raw data, rather than a webpage showing the file.

2.3.2.1 What is a Raw URL?

When you share files through platforms like GitHub, the standard URL typically leads to a webpage that displays your file. However, DICE needs a special type of URL - a raw URL - that leads directly to the file’s content. A raw URL usually follows this pattern:

https://raw.githubusercontent.com/username/repository/main/filename.csv

The key difference is that a raw URL starts with raw. in the domain name. This tells the server to send the pure file content rather than a webpage displaying the file.

2.3.2.2 Getting a Raw URL

If you’re using GitHub, you can find the raw URL by navigating to your file and clicking the “Raw” button. The URL in your browser will then show the correct format that DICE needs. If you prefer using Google Drive, you can share your CSV file and get a direct link. First, share the file by setting it to “Anyone with the link can view.” Then, instead of using the standard sharing link, modify it by replacing “file/d/” with “uc?export=download&id=” and removing everything after the file ID. Your Google Drive URL should look like this:

https://drive.google.com/uc?export=download&id=YOUR_FILE_ID

2.3.2.3 Using Your Raw URL

Once you have the raw URL, simply paste it into DICE where requested. The app will automatically fetch your configuration file and use it to set up your study.

2.3.3 CSV Delimiter

Your CSV file uses a special character to separate different pieces of data (like columns). While commas are the most common delimiter, some files use other characters. Select the character that matches your CSV file format - for example, if your data is separated by semicolons, choose “Semicolon” from the dropdown menu.

2.3.4 Hashtag

Enter the term you want participants to see in the search bar of your simulated social media interface. Using a hashtag or a username creates a more authentic social media experience, as it mimics how users typically search for content on platforms like Twitter. This search term will appear pre-filled in the interface’s search bar when participants start the study.

2.4 Participant Briefing

The briefing field allows you to create instructions that participants will see before they interact with the social media feed. This is where you provide context, tasks, or any other important information participants need to know.

Your briefing should be written in HTML format. This gives you control over how your text appears to participants. Here’s how you can format your briefing:

<h5>Welcome to our Study</h5>
<p>In this study, you will browse through a social media feed about climate change.</p>
<p>Please pay attention to the following:</p>
<ul>
    <li>Take your time reading each post</li>
    <li>Notice how people discuss the topic</li>
</ul>
<p><strong>Important:</strong> You will be asked questions about these posts later.</p>

Common HTML tags you might use:

<h5> for headlines
<p> for paragraphs
<strong> or <b> for bold text
<ul> and <li> for bullet points
<br> for line breaks

If you leave this field empty, the briefing page will be skipped entirely and participants will go directly to the feed.

2.5 Measurement

2.5.1 Survey Integration

After participants interact with the social media feed, you can redirect them to a survey. Simply provide the base URL of your survey (for example, a Qualtrics survey URL) without any additional parameters. DICE will automatically:

Add the participant’s ID to track responses
Include a completion code (which is useful if you’re using Prolific)
Handle the redirect process

For example, if you’re using Qualtrics, your URL might look like this: https://unisg.qualtrics.com/jfe/form/SV_0DnMoLpM0VxjhrM.

If you leave this field empty, participants will see a closing screen with your contact information instead of being redirected to a survey.

2.5.2 Dwell Time Tracking

The dwell time tracking threshold determines when DICE considers a social media post as “viewed” by the participant. This setting is expressed as a percentage of the post’s visibility in the participant’s browser window:

A threshold of 75% (default) means a post must be 75% visible to be considered “in view”
Lower values (closer to 1%) will count posts as viewed even when barely visible
Higher values (closer to 100%) only count posts that are almost fully visible

Choose your threshold based on how strictly you want to measure post exposure. For most studies, the default value of 75% provides a good balance between capturing meaningful exposure while allowing for natural scrolling behavior.

2.6 Create Session

After clicking “Create Session,” you’ll see a confirmation screen that contains all essential information for running your study and collecting data.

2.6.1 Saving Your Session Information

The success screen displays your unique session code (such as h4qfjieu) and a corresponding session URL. These identifiers are crucial as they provide the only way to monitor your study’s progress and download your data later. Make sure to save both the code and URL in a secure location for future reference.

2.6.2 Prolific Integration

This section is relevant only if you’re using Prolific for participant recruitment.

The success screen provides a specially formatted URL that includes Prolific’s parameter structure. It looks similar to this:

https://ibt-hsg.herokuapp.com/join/pifararu/?participant_label={{%PROLIFIC_PID%}}&prolific_study_id={{%STUDY_ID%}}&prolific_session_id={{%SESSION_ID%}}

Copy this entire URL and paste it (as is) into your Prolific study details. The URL contains three important placeholders:

{{%PROLIFIC_PID%}} captures each participant’s unique identifier
{{%STUDY_ID%}} tracks your specific study
{{%SESSION_ID%}} records individual participant sessions

You’ll also find a field to enter your Prolific completion code. This code needs to be entered and submitted to allow participants to confirm their participation after completing your study. The system automatically handles the completion code distribution to eligible participants, ensuring proper compensation through Prolific’s system.

This setup creates a smooth data collection process where all necessary identifiers are automatically tracked and your DICE data can be easily merged with your survey responses.