TAG's as a Grammatical Formalism for Generation

Tree Adj~g Grammars, or "TAG's', (Josh/, Levy & Takahash/ 1975; Josh/ 1983; Kroch & Josh/ 1965) we~ developed as an al~ma~ive to the aandard tyntac~ formalisms that are ,,_~'~ in theoretical ~,.ll,/~s of languaSe. They are a.rwac~ve because they may pin,vide just the asFects of context seusit~ve exptes~e Fmv~r that actually appear in human lanSuages while otherwise r ~ a l n i n g context free. "['n/s paper ___~,~,ibcs how we have applied the theory of Tree Adjoining Grammars to natural language generation. We have ~ attracted to TAG's because their cemral opemtiou--~he exteamou of an "initial" phra~ m~ca~u tree through the incl~/ou, at re,? , ~ y came~/aed loeatinus, of oae or mmu "au~!!iar~'* ~ d s dixec~ to cextain ceat~ ol~rat~m of our owu, p~rfonnnce-one~ted theory. We besm by briefly _,~,,-,ibin 8 TAG's u • formalism for phrase ram:rare in a com~___~ theory, and summar/ze the points in the theory of TAG's that are germainu to our own theory. We them conmdm' generaUy the poation of a grammar within the geueratiem process, inemducmg our use of TAG's through a contrast with how oth~nJ have used system~ grammars. This takes us to the ,~,~,~ resulm of our psper:, usng eaamp/es from our research with wefl.wrR1eu trots from aewupapmm, we walk throush our TAG insp/~ed treatments cl r ~ n g and wh-movemem, and show the cc~denc~ of the T A G ~adjunct/oo" oper~t/oa and our "attachment" process. In the final tectiou we discuss ~mau/ons to the theory, motivated by the way we usa the operafiou cmveqxmdin 8 to TAG's" adjun~iou in performance. This mssesss that the compe~eace theory of TAG' s can be profitably projoc~ed to s~na:tur~ at the morphoiogicaJ leve/ as weft as the preseat syntacuc level 2. Tree Ad]unctioo Grammars