KEYWORD EXPANSION METHOD AND SYSTEM, AND CLASSIFIED CORPUS ANNOTATION METHOD AND SYSTEM

摘要

Provided are a method and system for keyword expansion; the method performs a search by means of an initial keyword, the searched and obtained keyword serving as the basis for the next search, and the searches being performed by means of keyword iteration; when the error of two consecutively searched keywords is within a certain range, the searched keyword serves as an expansion keyword of the initial keyword; in this way, various expressions of the initial keyword and multi-faceted implied meanings of the word are obtained, and the initial keyword is effectively and reasonably expanded, solving the problem in the prior art requiring that a corpus be manually established; the method is a convenient and highly accurate method for keyword expansion. Also provided is a method and system for classifying corpora and automatic annotation; the method determines for each class one or more initial core keywords; expanded keywords of each class are obtained by means of initial core keyword expansion; a search is performed using the expanded keywords corresponding to the classes, and a class corpus is selected therefrom and annotated.