This simple intervention is a message for new users of a platform or new members of an online community.

It has three key elements:

1. A link to what is considered trolling in the community or platform
2. A warning that users will sometimes see trolling, but that non-trolls outnumber the trolls
3. Instructions for how to handle trolls

This intervention has been shown to:

1. Increase retention of users who join the community in good faith.
2. Those users know beforehand that trolls are present, and they therefore have the tools to deal with them, and are less likely to be scared away from the platform by harassment.
3. Increase proportion of good-faith users to those who join as provocateurs, &c.

Where this intervention was used, the increase in retention was limited to those who actively identified with the mission of the community.

Retention did not increase among those revealed not to be joining in good faith.

This can appear as an automated comment to a new user's post, as an automated personal message, or as an interstitial upon entry.

Researchers at Cornell's Citizen and Technology Lab conducted a two-year project with r/feminism on Reddit to test an idea for reducing harassment.

They found that "messages explaining that harassers were a minority increased newcomer comments by 20% on average, an effect that persisted across the full 10 weeks we collected data (n=1,300; p=0.002)."

This intervention could be useful for reassuring and empowering marginalized voices who would otherwise be silenced by hostility.

This could also help with polarization as it helps newcomers and outsiders to an online community more accurately see hostile users as the minority they are, rather than seeing them as representative of the entire community and treating that community accordingly.