Connectionist accounts of inflectional morphology have
focussed on the domain of the English Past Tense (e.g.
Rumelhart & McClelland 1986; Plunkett & Marchman
1993). In this inflectional domain, the default mapping
process (add /ed/) reflecLs the process of suffixation
adopted by the majority of the forms in the language.
Connectionist models exploit the imbalance between
EngHsh regular and irregular verbs when learning the
past tense and when responding to novel forms in a
default fashion. Not all inflectional systems have a
default mapping which is characterized by a majority of
forms in the language. The Arabic Plural System has
been cited (Marcus et al. 1993) as one such system
where a minority default mapping process operates. The
Sound Plural in Arabic applies to only a minority of
forms in the lexicon (~104;), yet it appears to adopt the
role of a default mapping for novel nouns. W e describe a
connectionist model that can learn a minority default
mapping analogous to the Arabic plural and discuss its
performance in relation to type and token frequency
effects, and their distribution within phonetic space.