ELIZA, a computer program for the study of natural language communication between man and machine

Eliza is a program operating within the MAC time-sharing system at MIT which makes certain kinds of natural language conversation between man and computer possible. Input sentences are analyzed on the basis of decomposition rules which are triggered by key words appearing in the input text. Responses are generated by reassembly rules associated with selected decomposition rules. The fundamental technical problems with which ELIZA is concerned are: (1) the identification of key words, (2) the discovery of minimal context, (3) the choice of appropriate transformations, (4) generation of reponses in the abscence of key words, and (5) the provision of an editing capability for ELIZA "scripts". A discussion of some pyschological issues relevant to the ELIZA approach as well as of future developments concludes the paper.