REBEKAH PARK Gemic DAVID ZAX ReD Associates BETH GOLDBERG Jigsaw This 2019 project conducted in the US and the UK sought to understand which conspiracy theories are harmful and which are benign, with an eye towards finding ways to combat disinformation and extremism. This case study demonstrates how ethnographic methods led to insights on what “triggered” conspiracy belief, the social and emotional roles conspiracy theories played in believers’ lives, and how conspiracy belief was often a reflection of a person's general sense of societal alienation. We discovered that any extreme version of a conspiracy theory could be harmful. The findings of this project changed how the client—and by extension engineers behind major tech platforms—understood harmful conspiracy-related content, and led to a refinement of the algorithms defining the discoverability of this content. The aim of this project was to scale and amplify through algorithmic interventions the work of individual debunkers. Keywords: Conspiracy theories,...