Associative model of morphological analysis an empirical inquiry.pdf

ASSOCIATIVE MODEL OF MORPHOLOGICAL ANALYSIS: As EMPIRICAL INQUIRY 1 H a r r i J i i p p i n e n 2 a n d M a t t i Y l i l a m m i 2 Helsinki Universi ty of Technology Helsinki, Finland This paper presents a computational model for the analysis of word forms of a highly inflectional, agglutinative language. We call the model associative as it directly links phonemic stimulus with its morphemic interpretation(s) under the guidance of a coherence constraint. The model has been fully implemented for Finnish. We discuss separately the abstract model and various algorithms to implement the model. We also demonstrate the implementation. The best features of the method are its efficiency and its capability of supporting open lexicons. 1 INTRODUCTION In the search for computational models of language, syntactic analysis of sentences has so far received much greater attention than morphological analysis of word forms. For example, Winograd (1983) in his thorough book on syntax and parsing methods has allocated six or so pages to the morphological analysis. That makes about one percent of the whole text. This does not, of course, mean that the author rates morphology unimportant, but it does, we believe, reflect the general interest of the research community. Such heavy emphasis on syntax on the one hand and almost total neglect of morphology on the other follows from the idiosyncracies of English. And due to the domi- nant role English has in the computational linguistic community, this somewhat unbalanced view permeates the computational linguistic literature. The neglect of English morphology has obvious reasons. The basic rules of English word inflection are quite simple. There are some fusion phenomena that produce portmanteau morphs resistant to inflectional analysis, but their number is small. For syntactic analysis of sentences, one needs a lexicon anyway. Why not then take the easy way out and let the lexicon bear the b