Recent experiments in programming natural language question-answering systems are reviewed to summarize the methods that have been developed for syntactic, semantic, and logical analysis of English strings. It is concluded that at least minimalty effective techniques have been devised for answering questions from natural language subsets in small scale experimental systems and that a useful paradigm has evolved to guide research efforts in the field. Current approaches to semantic analysis and

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... ogical inference are seen to be effective beginnings but of questionable generality with respect either to subtle aspects of meaning or to applications over large subsets of English. Generalizing from current small-scale experiments to language-processing systems based on dictionaries with thousands of entries--with correspondingly large grammars and semantic systems--may entail a new order of complexity and require the invention and development of entirely different approaches to semantic analysis and question answering. Volume 13 / Number 1 / January, 1970 Communications of the ACM 15 16 Communications of the ACM Volume 13 / Number 1 / January, 1970 18 C o m m u n i c a t i o n s of t h e ACM V o l u m e 13 / N u m b e r 1 / J a n u a r y , 1970