A new account of parameter setting during grammatical acquisition is presented in terms of Generalized Categorial G r a m m a r embedded in a default inheritance hierarchy, providing a natural partial ordering on the setting of parameters. Experiments show that several experimentally effective learners can be defined in this framework. Ew)lutionary simulations suggest that a with default initial settings for parameters will emerge, provided that learning is memory limited and the environment of linguistic adaptation contains an appropriate language. .
