Sorry for the slow response. Our model is - we think - an advance because it actually allows us to infer the amount of shared structure between different words. This is an index of how much generalization the child is doing. If they do no generalization, that's evidence for what's called "item specific learning" (no abstract grammatical rules). If they do complete generalization, that's the innateness hypothesis in the paper I linked. What we found was - of course - a mixture, but critically with something close to item-based learning in the very earliest data from the very youngest kids.