[developers] Re: Ranking parses

Berthold Crysmann crysmann at dfki.de
Wed May 11 16:51:54 CEST 2005

Stephan Oepen wrote:

>hi petter,
>>There are some students here at NTNU who use my grammar in a small
>>question-answering application and they have a problem with picking the
>>right parse. Is there an easy way to use an itsdb treebank (if we build
>>it) to rank the parses?
>apologies for the long turn-around time.  yes, it is possible to build
>a (small-ish, maybe) treebank using [incr tsdb()] facilities, and then
>train a Maximum Entropy parse selection model on it.  i would estimate
>that 500 -- 1500 annotated sentences should be sufficient to make the
>model perform reasonably well (on a coherent domain).  also, PET comes
>with good support for parse ranking using ME models, while the LKB has
>most of the required functionality,

just curious: how do I activate this functionality in the LKB for 
parsing and/or generation?


> but the interface is a little more
>involved (and less tested).  finally, estimating the model once there
>is training data requires that the `estimate' package by Rob Malouf is
>installed locally, which in turn requires some third-party libraries.
>--- all doable, but i would hesitate to call the procedure `easy' :-{.
>needless to say, hardly any of this is documented, although i know at
>least francis is eager to write up what is known about the process ...
>should you not feel discouraged at this point, i would be happy to help
>remotely, but realistically do not have that much time available.  erik
>knows everything about the training aspects, once you had the data, and
>generally enhancing NorSource with an initial ME model would seem like
>a nice thing.  would you have people to do the annotation?  as the main
>developer of the grammar, you should get someone else to annotate :-).
>                                                   all the best  -  oe
>+++ Universitetet i Oslo (ILN); Boks 1102 Blindern; 0317 Oslo; (+47) 2285 7989
>+++     CSLI Stanford; Ventura Hall; Stanford, CA 94305; (+1 650) 723 0515
>+++       --- oe at csli.stanford.edu; oe at hf.uio.no; stephan at oepen.net ---

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