Experimental Design Details
The primary purpose of the experiment is to measure the effect of an intervention that reduces exposure to toxic social media content on mental health of users, and to understand the mechanisms linking toxicity and mental health. This study is conducted simultaneously with an RCT registered under the following title “Social Media Toxicity and Political Attitudes”. The trial was registered by Mateusz Stalinski (University of Warwick).
We recruit participants to install a browser extension called "Social Media Research", which has the ability to hide toxic content (posts, comments, replies) on Twitter, Facebook, and Reddit. The extension was specifically designed for Google Chrome browser. The extension may work on other Chromium browsers, but this functionality was not tested. Recruitment is conducted both via social media ads and using survey companies (such as CloudResearch). We will recruit in two waves, the first one in the summer of 2024 (approximately 1,000 people) and the second one in the fall (starting in mid-November). We will include wave fixed effects in our analysis.
Users are randomized into one of 3 groups. In the treatment groups, during the intervention period all content exceeding a set threshold level of toxicity is hidden (please see Intervention section for details, including a description on how we assign toxicity scores). There will be two treatment groups that will use different combinations of classifiers to flag toxic content (see Intervention section). In the control group, half of the respondents will experience random hiding of content. The other half of the control group will not experience any hiding. We will use the following probabilities of assignment to different treatment groups:
- Treatment 1 (first classifier): 30% chance,
- Treatment 2 (second classifier): 30% chance,
- Control: 40% chance (which means an overall 20% chance of random hiding control and a 20% chance of pure control).
After installation and completion of a baseline survey, the user enters an intervention period of 6 weeks, where the extension hides toxic/random content in the groups where this is required. After 6 weeks, we will survey the respondents again in a midline survey phase. After that, the respondents will keep using the extension for 4 weeks before an endline survey. During that time (after the midline survey), the respondents in the control group will be cross-randomized in two groups where they will either experience an intervention that instrumentates user engagement (e.g., changing latency of the page/feed) or not. The goal is to quantify the direct effect of toxicity hiding on outcome variables as well as establish what part of the treatment effect operates through varying user engagement, which in turn affects the outcomes.
The primary outcome and secondary outcomes 1-3 will be measured in all three surveys (baseline, midline, endline). In order to test whether hiding toxicity has an impact on these outcomes, we will use a canonical difference-in-difference specification with outcomes measured in two periods (baseline survey and midline survey) and two treatment groups (toxicity hiding with both sets of classifiers pooled vs. controls pooled). We consider this approach our main specification. This approach takes into account the high overlap in the type of content flagged as toxic by the two sets of classifiers that we employ. We will separately look at whether the additional usage of Alienation classifier led to heterogeneous treatment effects. For secondary outcomes 4-5, which are only measured in either midline or endline surveys, we will rely on between subjects mean comparisons between treatment groups (for the main specification, we will compare toxicity hiding with both sets of classifiers pooled vs. controls pooled).
Before fielding the endline survey of the study starting the week of 21st October, we want to amend the pre-registration by adding a few questions to the endline survey to understand additional mechanisms. These are the additional questions:
a) In the past weeks, did social media make you feel you were missing out on important information, experiences and/or discussions? (Likert scale 5 points)
(b) UCLA 3-item (we will index the responses):
- First, how often do you feel that you lack companionship: Hardly ever, some of the time, or often?
- How often do you feel left out: Hardly ever, some of the time, or often?
- How often do you feel isolated from others? (Is it hardly ever, some of the time, or often?)
(c) In the past four weeks, how often have you felt angry? (Likert scale 5 points)
We will compare the additional outcomes across experimental conditions using the same specifications described above.