Lab notebook: improving topic modeling for digital political ads

C4D is building better ways to understand how advertisers try to influence the public

Example of search on the topic “abortion” on Ad Observatory.
C4D’s new approach to modeling topics on Ad Observatory.
In this diagram, each vector represents an ad. The cosine of the angle between two vectors is described as cosine similarity.
Clustering ads by cosine similarity allows human reviewers to identify new trends in political ad messaging.



Cybersecurity for Democracy ( is a research-based effort to expose online threats to our social fabric — and recommend how to counter them. We are part of the Center for Cybersecurity at NYU.

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