Skip to Main Content
This paper presents the design of a broad-coverage Japanese sentence analyzer which can be part of various Japanese processing systems. The sentence analyzer comprises two components: the lexical analyzer and the syntactic analyzer. Lexical analysis, i.e., segmenting a sentence into words, is a formidable problem for a language like Japanese, because it has no explicit delimiters (blanks) between written words. In practical applications, this task is made more difficult by the occurrence of words not listed in a dictionary. We have developed a five-layered knowledge source and used it successfully in the lexical analyzer, resulting in very accurate segmentation, even in cases where there are unknown words. The syntactic analyzer has two modules: One consists of an augmented context-free grammar and the PLNLP parser; the other is the dependency structure constructor, which converts the phrase structures to dependency structures. The dependency structures represent various key linguistic relations in a more direct way. The dependency structures have semantically important information such as tense, aspect, and modality, as well as preference scores reflecting relative ranking of parse acceptability.
Note: The Institute of Electrical and Electronics Engineers, Incorporated is distributing this Article with permission of the International Business Machines Corporation (IBM) who is the exclusive owner. The recipient of this Article may not assign, sublicense, lease, rent or otherwise transfer, reproduce, prepare derivative works, publicly display or perform, or distribute the Article.