CRITAC - A Japanese Text Proofreading System

CRITAC (CRITiquing using ACcumulated knowledge) is an experimental expert system for proofreading Japanese text. It detects mistypes, Kana-to-Kanji misconversions, and stylistic errors. This system combines Prolog-coded heuristic knowledge with conventional Japanese text processing techniques which involve heavy computation and access to large language databases. 1. I n t r o d u c t i o n Current advances in Japanese text processing are mainly due to the remarkable growth of the word processor market. Machine readable Japanese text can now be easily prepared and distributed. This trend spurred the research and development of further text processing applications such as machine translation and text-to-speech conversion [SAKAS8310] [MIYAG8310]. However, some fundamental text processing procedures are missing for Japanese text. For example, counting the number of words in text is a difficult task since words are not separated by blanks. Our experimental system CRITAC (CRITiquing using ACcumulated knowledge) tries to overcome Japanese language problems. Proofreading (or critiquing, to some extent) [CHER80] [HEIDJ82] has been chosen as our research domain because it involves many text processing techniques and is one of the most important functions currently required and lacking. In this paper, we introduce CRITAC concepts and facilities including a conceptual representation of Japanese text called "structured text" to handle meaningful objects (e.g., sentences and words) and proofreading using heuristic rules for the structured text. The structured text consists of a set of Prolog [CLOCMS1] facts and predicates, each of which represents an object or a class of objects in the text. Because of this high-level representation, human proofreading knowledge can be easily mapped into Prolog rules. Two user-friendly representations of text, called "source" and "KWlC" (Key-Word-In-Context) views, are derived from the structured text. CRITAC provides users with editing and proofreading functions defined over these views. The notion of structured text, we believe, is not restricted only to the Japanese language. Discussions on our approach for languages other than Japanese will be given in the Conclusion. 2. CRITAC System Overview In this section we discuss the outline of CRITAC and its underlying concepts. As shown in Figure 1, the heart of CRITAC lies in its architecture. It consists of three major components: a user interface, a preprocessor, and a proofreading knowledge base. Word Processor F Text Compiler Machine Readable] SQL/DS Dictionary Server Text [ ['II FText Editor file~J transfer / ~ ~ PRIPROCESS;R / I View [View _J • I USER INTERFACE segmentaUon I [ word recognition [ I / ~ I PROOFREADING ~,k I KNOWLEDGE BASE stored %~. I ' "--I "~"-~[ Structured Text] Figure 1. CRITAC Configuration: The preprocessor generates the structured text from given text. The proofreading knowledge base currently consists of about 30 Prolog proofreading rides for the structured text. The user interface handles two external views and facilitates the SQL/DS online dictionary server and text compiler.