OPEN-WEIGHT
You can download the trained parameters. That does not mean the whole recipe is sitting beside them.
WHAT DOES IT ACTUALLY MEAN?
An open-weight model makes its trained numerical parameters available for others to download and run. Training data, source code, methodology and licences may remain restricted.
WHY ARE WE TRACKING IT?
Open weights let independent researchers reproduce tests, inspect behaviour and run longitudinal experiments without a provider silently changing the underlying system.
KEEP ONE EYEBROW UP.
Open-weight is not automatically open source, safe, transparent or ethically trained. Read the licence and keep the receipt.
RECEIPTS & REVISIONS.
Use this definition as the reading key for Model Watch. A capability claim only moves an AICNW assessment when the dated evidence meets the framework—not because a model said something dramatic on the internet.