On Wed, Apr 9, 2008 at 6:03 AM, Stephen Reed <[EMAIL PROTECTED]> wrote: > > I would be interested > in your comments on my adoption of Fluid Construction Grammar as a solution > to the NL to semantics mapping problem. > (1) Word Grammar (WG) is a construction-free version of your approach. It is based solely on spreading activation. It doesn't have a sharp separation of syntax and semantics: there's only one net. Nodes representing subgraphs corresponding to constructions can be organized into inheritance hierarchies (extensibility). But "pure WG" makes things very awkward logics-wise, making it work would be a lot of research (the WG book doesn't discuss utterance generation IIRC, but reversing parsing-interpretation seems quite direct: select the most activated word which doesn't have a left landmark, introduce a word-instance node for it, include spreading its activation through a right-landmark (ignoring direction of the landmark) edge). Texai is impure by its very nature, perhaps it could be made more (than just sharing the spreading activation idea) of a mix WG*FCG.
(2) FCG is closer to traditional apporaches a la "computational linguistics" than WG. (3) One could give up some FCG features to simplify it, for example by assuming one-to-one correspondence between constructions and atomic predicates. (4) I'm interested in how do you handle backtracking: giving up on application of a construction when it leads to inconsistency. Chart-based unification parsing can be optimized to share applications of constructions which are "parallel", and this can be extended to operators which are (like unification) monotonic, e.g. cannot make unsatisfiable/inconsistent state a satisfiable/consistent one. Merging conjuncts new facts to old ones so it is monotonic in monotonic logics. (Default/defeasible logics are nonmonotonic.) (4a) Does the fact that your parser is incremental mean that you do "early commitment" to constructions? (Double R Grammar seems to support early commitment when there is choice, but backtracking is still needed to get an interpretation when there are only ones without it.) I will get to studying your sources when I'll have some time... ------------------------------------------- agi Archives: http://www.listbox.com/member/archive/303/=now RSS Feed: http://www.listbox.com/member/archive/rss/303/ Modify Your Subscription: http://www.listbox.com/member/?member_id=8660244&id_secret=98558129-0bdb63 Powered by Listbox: http://www.listbox.com
