A Transformation of Concordance Data on Japanese Classics to Corpus Tagged with Part-of-Speech.

Abstract

A 'sou-sakuin' is a kind of concordance, which gives an alphabetical list of all words used in a book and shows all positions where each word can be found. It is useful as a tool for researching Japanese classics. A corpus with part-of-speech tags, which gives a collection of sentences and their part-of-speech data, is useful as a tool for natural language processing. However, there is no such corpus for Japanese classics. Thus, we try to transform 'sou-sakuins' into corpora with part-of-speech tags. Each ' sou-sakuin' we used consists of two parts: a text part and an index part. The index part consists of records, each of which has a headword (Kana-string, Kanji-string and part-of-speech data on each word) and an inverted list, which gives line numbers of text part where the word is found. In transformation program, we only use inflection tables for inflective words. We adopt a kind of longest-match method to resolve the problem of occurring of two or more words in a same text line, one of which is sub-string of another word. We also adopt a kind of look-ahead method for the headword's Kanji string which consists of only Kanji characters even if the corresponding text string of the word consists of Kanji and Kana characters. As a result, we got corpora on Japanese classics having about 150,000 words.