[Langutils-devel] Question on verb phrases

[Ian Eslick]

If you're using the github version, I just pushed a patch for the chunker.  A compatibility fix for the latest CCL caused a regression in the phrase patterns.  Thanks for reporting it!

'Show' defaults to NN and that particular sentence construction doesn't seem to allow the Brill rule tagger to figure out that it's a VB in that specific context.  I'm not sure if it was always like that, or it's a regression.  However, the tagger is using files trained on a news corpus which contains far less imperative statements so it's not too surprising.  "Can you tell me about the coats for winter" gets it right because tell is more obviously a VB.

Ian

On Oct 8, 2011, at 8:57 PM, Larry Hull wrote:

> Can anyone give me an example that generates a chunked verb phrase?
> 
> I'm having difficulty understanding the verb tags.
> 
> Consider the following string which is actually in the pdf in the docs "Show me all the coats for winter.
> 
> In Section 7.1 of the pdf, this should be chunked such that
> (VX Show VX) (NX me NX) (NX all the coats NX) (PX for winter PX)
> 
> But running tag generates:
> 
> (tag "Show me all the coats for winter")
> "show/NNP me/PRP all/DT the/DT coats/NNS for/IN winter./NN "
> 
> and running chunk generates:
> (chunk "Show me all the coats for winter.")
> (#<PHRASE:NX "show "> #<PHRASE:VX "show "> #<PHRASE:ADVP "show ">
>  #<PHRASE:NX "the coats "> #<PHRASE:VX "the coats ">
>  #<PHRASE:ADVP "the coats "> #<PHRASE:NX "winter. "> #<PHRASE:VX "winter. ">
>  #<PHRASE:ADVP "winter. ">)
> 
> The tag show no verbs whatsoever, the chunk has show as noun, verb and adverb phrases.
> 
> If I tag the string "The dog ate his food"
> 
> (tag "The dog ate his food")
> "The/DT dog/NN ate/VBD his/PRP$ food/NN 
> 
> "ate" is clearly labeled as a verb, but when I chunk the same string
> 
> (chunk "The dog ate his food")
> (#<PHRASE:NX "the dog "> #<PHRASE:VX "the dog "> #<PHRASE:ADVP "the dog ">
>  #<PHRASE:NX "his food "> #<PHRASE:VX "his food "> #<PHRASE:ADVP "his food ">)
> 
> the word "ate" disappears completely and "the dog" and "his food" are NX, VX and ADVP.
> 
> Clearly I'm misunderstanding something. Can someone shed a little light on my ignorance?
> 
> Larry
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