Overgeneration is a property of (word formation) rules which entails that they are able to generate entities which are fully well-formed, but are not attested or used by the native speakers of a language.
if the rule for -al affixation may derive attested forms such as arrival and refusal as well as unattested forms such as derival and describal, we say that the -al rule overgenerates.
- Halle, M. 1973. Prolegomena to a Theory of Word-Formation, Linguistic Inquiry 4, pp. 451-464
- Spencer, A. 1991. Morphological Theory, Blackwell, Oxford.