eval — A repeatable test for AI quality — a set of tasks plus scoring — used the way software teams use test suites, because model output is too variable to judge by eyeballing.
open weights — A model whose trained parameters are published for anyone to download and run — unlike API-only models you can access but never possess.
pretraining — The first, biggest phase of building a model: training it on enormous amounts of text so it learns language, facts, and reasoning in general.
Why it matters
The results quantify how far pre-release mitigation moves NCII and CSAM vulnerability in open weightsA model whose trained parameters are published for anyone to download and run — unlike API-only models you can access but never possess.Full definition → image models, and the paper argues deployment-side moderation covers most residual risk. That conclusion is directly relevant if you self-host image generation.
