Semantic interpretation in linear time in the ATIS domain

摘要

People understand utterances in real time. Blank [1] described a natural language processor which also parses sentences in linear time. Like human performance, it stays within fixed and finite short-term memory—indeed, these limits prevent it from being overwhelmed by syntactic ambiguities. This paper reviews the parser and describes enhancements that allow it to perform morphosyntactic agreement and semantic interpretation—still within linear time and with predictable resources. The lexicon has been extended semi-automatically, using data from tagged corpora and WordNet, to cover the typical vocabulary of utterances in the domain of air traffic information service (ATIS). Comparing our interpreter with the performance ofPundit's top down parser [2] for utterances in the ATIS domain, we get improvements of at least an order of magnitude and avoid asymptotic cases due toPundit's unbounded backtracking.