Short summary of Condensation

Condensation is a theory of concepts by Sam Eisenstat. The paper can be read here. Abram wrote a review on Lesswrong, and a followup. The paper is very much worth reading, and can be skimmed to just understand the motivation if you’re time constrained.

What is a concept? One rough pointer is "the little packets of information that are the meaning of a word or phrase". Another is the clusters found in the cluster structure of thingspace. Maybe we could think of them as little chunks of a generative model that compose together to make complete model of a complex world.

It often seems to be the case that this kind of chunking is arbitrary, in the sense that there isn’t one way to chunk up a generative model. It just depends on the hypothesis class, prior and implementation details. But some concepts seem to be more objective than this, in that we would expect different agents with different implementation details to use the same concept. One question that Condensation answers is “under what conditions can concepts be more objective?”. The theory provides some assumptions and metrics that can be used to select among latent [...]