Janet Fodor
Department of Linguistics
City University of New York
(Joint work with William Sakas, Hunter College and Graduate Center, CUNY)
The Subset Principle is essential to avoid overgeneration in language acquisition, on two widely-held
assumptions: (a) there is insufficient negative data to disconfirm all overgeneral hypotheses any learner might
be tempted to adopt in the absence of SP; (b) it is not practical to rely on retreat mechanisms to cure all such
imaginable overgeneration errors after they have occurred. Despite this, no currently implemented model of human
syntax acquisition (including our own) incorporates the Subset Principle. Why is this so? Our observations
suggest that implementing the Subset Principle demands unrealistic resources of either on-line computation or
memory. Before adopting a grammar Gi in response to input, the learner would have to check out all grammars which
generate proper subsets of Gi's language to see whether any of them could accommodate the input. One scheme for
reducing this vast labor is Manzini & Wexler's proposal that subset choices can be made simply by favoring the
default value of each parameter. In our research we have discovered that this needs serious reinforcement if it
is to contend with challenges such as: how does the learner establish which parameters are candidates for
resetting; what if more than one parameter needs resetting at a time; when one parameter is set 'forward' to its
non-default value, SP requires all others to be set back to their defaults; in incremental learning (widely
assumed) the learner knows only its current grammar and its current input sentence, so adopting the smallest
language compatible with the available input means adopting an absurdly small language lacking most of the
phenomena the learner had previously acquired. We welcome your suggestions about how to cope with these problems.
At present no definitive solution is known, but we are exploring the benefits of adding some memory for past
inputs and/or past grammar hypotheses.
Reception to follow in 1413 Marie Mount Hall.