Pragmatic Question Answering: Generic Versus Specific Responses

Abstract

Asking questions is a fundamental human activity. Questions of the form VVhat objects X have property Y? ” can be viewed as having two types of responses: specific (extensional) and generic (intensional). A spe-cific response to the question “Who got a raise this year? ” is a list of individuals who got a raise this year. A generic response to this question is a description of the, criteria used in determining who got a raise, for example, “all employees with greater than five years of service and good reviews”. The focus of this research is to determine the circumstances that dictate whether a generic or specific referent constitutes the most ap-propriate response to a question. The most appropriate response to a question is one that best conforms to Gricean maxims of conversation (Grice 1975)- guidelines that describe cooperative conversational behavior. For example, it is critical that a response not mislead a questioner. Kaplan ad-dresses this problem with respect to failed presuppo-sitions (Kaplan 1981). When a questioner asks how many students received ‘F ’ grades in a particular lin-guistics course, if no such students can be found many computer systems will respond “none ” even if the lin-guistics course in question does not exist. A coopera-tive response in this case should indicate that there is no such course. Specific responses fail to correct misapprehensions and do not inform a questioner about general proper-ties that can enhance her overall understanding of a set of data. Generic responses may be evasive if what is desired is a list of facts. A computer system that is not capable of responding appropriately can mislead and frustrate a user. A number of researchers have worked on the problem of providing cooperative response to questions. Recent work by Gaasterland, Godfrey, and Minker (Gaaster-land, Godfrey, & Minker 1994) provides a foundation