From - Mon Apr 19 11:17:02 2004 X-Mozilla-Status: 0001 X-Mozilla-Status2: 00000000 Path: acsu.buffalo.edu!rapaport From: rapaport@cse.buffalo.edu (William J. Rapaport) Newsgroups: sunyab.cse.740 Subject: MOD-HEAD CASE FRAME Date: Fri, 16 Apr 2004 19:42:34 -0400 (EDT) Organization: Computer Science and Engineering Lines: 45 Sender: Ncs@buffalo.edu Distribution: sunyab Message-ID: NNTP-Posting-Host: castor.cse.buffalo.edu X-Trace: prometheus.acsu.buffalo.edu 1082158954 22180 128.205.32.14 (16 Apr 2004 23:42:34 GMT) X-Complaints-To: abuse@buffalo.edu NNTP-Posting-Date: Fri, 16 Apr 2004 23:42:34 +0000 (UTC) X-Newsreader: trn 4.0-test76 (Apr 2, 2001) Xref: acsu.buffalo.edu sunyab.cse.740:112 ------------------------------------------------------------------------ Subject: MOD-HEAD CASE FRAME ------------------------------------------------------------------------ Several of you have asked for the syntax and semantics of the mod-head case frame. There isn't any official one, and we have been using it in a rather informal way. Making it precise would probably be the topic of a full-blown master's-level project. The general idea is to use it to represent compound linguistic constructions that are ambiguous in nature. Compare, for a moment, the infamous object-rel-possessor case frame that many of you have come to know and "love" :-). The idea behind that one is that the possessive construction in English (as in: Bill's book, her hat, etc.) is a single, compound linguistic construction that is variously used to express ownership, part-whole, kinship, and many other relations. Since a parser wouldn't necessarily have the information necessary to interpret each such occurrence correctly, we handle them by representing that single English construction with a single case frame, leaving to background knowledge any rules that are needed for the full semantic interpretation. There are other such compound constructions. The most obvious is the adjective-noun noun phrase: red hat, small elephant, toy gun. Each of these should be represented as a structured individual in SNePS, but each has a very different semantics: a red hat is both a hat and red; but a small elephant is an elephant, yet not small (although it *is* small for an elephant); and a toy gun is a toy, but not a gun. Instead of SNePS having to know ahead of time how to represent each such expression, we can use the mod-head case frame as a "neutral" representation, leaving to background knowledge the task of deciding what kind of Adj+N construction it is. We also tend to use the mod-head construction for other situations; perhaps we shouldn't. So, here's a first attempt at a case frame (I'll ask Stu if he has a better idea): [[(build mod x head y)]] = a structured individual consisting of an individual [[y]] modified by [[x]]. That's pretty vague, but then the mod-head case frame is, too.