Network Morphology is a formally explicit approach to morphology which
distributes information across a network in which generalizations can
be optimally expressed. Generalizations become available in specific
cases by the operation of default inheritance. In this paper we explor
e the notion of 'default' in morphology by means of a Network Morpholo
gy analysis of the noun classes and genders of Arapesh - a language wh
ich relies on a sophisticated understanding of defaults for a satisfac
tory treatment (Aronoff, 1992). Our work lends support to Aronoff's ac
count of the Arapesh data. It also reveals a confusion in use of the t
erm 'default' by linguists. In one usage of the term, the ('normal cas
e') default is that which applies in the absence of blocking informati
on; in the other, the ('exceptional case') default is that which appli
es when some exceptional factors prevent normal processes from applyin
g and necessitate the adoption of some 'last resort' solution. Under o
ne reading the default equates with the unmarked case; in the other, i
t is the marked case which is picked out by the same term.