Phrasal analysis of long noun sequences

Abstract

Noun phrases consisting of a sequence of nouns (sometimes referred to as nominal compounds) pose considerable difficulty for language analyzers but are common in many technical domains. The problems are compounded when some of the nouns in the sequence are ambiguously also verbs. The phrasal approach to language analysis, as implemented in PHRAN (PHRasal ANalyzer), has been extended to handle the recognition and partial analysis of such constructions. The phrasal analysis of a noun sequence is performed to an extent sufficient for continued analysis of the sentence in which it appears. PHRAN is currently being used as part of the SPAN (SPecification ANalysis) natural language interface to the USC Advanced Design AutoMation system (ADAM) (Granacki ct at, 1985). PHRA_N-SPAN is an interface for entering and interpreting digital system specifications, in which long noun sequences occur often. The extensions to PHRAN's knowledge base to recognize these constructs are described, along with the algorithm used to detect and resolve ambiguities which arise in the noun sequences.