Taking the Initiative in Natural Language Data Base Interactions: Justifying Why

In answering a factual database query, one often has the option of providing more than just the answer explicitly requested. As part of our research on Natural Language interactions with databases~ we have been looking at three ways in which the system could so "take the initiative" in constructing a response: (i) pointing out incorrect presuppositions reflected in the user's query [4,5]; (2) offering to "monitor" for the requested information or additional relevant information as the system learns of it [6,7]; and (3) providing grounds for the system's response i.e., "justifying why". The following responses illustrate "presupposition correctlon"~ "monitor offers" and "justification", respectively. This paper describes our research on producing justifications. ("U" refers to the user, "S" to the system.)