 Students of conversation analysis have contended precisely this, remarking that many speech acts fall naturally into pairs.[17] For instance, questions pair naturally with assertions when the latter purport to be answers to those questions. Likewise, offers pair naturally with acceptances or rejections, and it is easy to multiply examples. Searle, who favors studying speech acts in isolation, has replied to these considerations (Searle 1992).  There he issues a challenge to students of conversation to provide an account of conversations parallel to that of speech acts, arguing as well that the prospects for such an account are dim. One of his reasons is that unlike speech acts conversations do not as such have a point or purpose. Green 1999 rejoins that many conversations may indeed be construed in teleological terms. For instance, many conversations may be construed as aimed at answering a question, even when that question concerns something as banal as the afternoon’s weather or the location of the nearest subway station. Asher and Lascardes (2003) develop a systematic treatment of speech acts in their conversational setting that also responds to Searle’s challenge. Additionally, Roberts (2004, 2012) develops a model of conversational kinematics according to which conversations are invariably aimed at answering what she terms a question under discussion (QUD). This view is best appreciated within the framework of the “scorekeeping model” of conversation, to which we now turn.