Do the experts specialize by topic?

A natural guess is that one expert becomes "the math expert" and another "the poetry expert." Interestingly, the paper found the specialization is more subtle than that. The router's choices often track patterns of grammar and structure rather than clean human topics. The important point for a beginner is simply this: the model learns on its own how to divide the labor among experts, just as the Transformer learned what to attend to in Chapter 1. Nobody assigns the experts their jobs by hand.