[Corpora-List] POS-tagger maintenance and improvement

Brett Reynolds brett at forsyths.ca
Thu Feb 26 03:18:12 CET 2009

On 25-Feb-09, at 8:04 PM, WHITELOCK, Pete wrote:

> In this regard, the labeling of "last Sunday" as
> an adverb seems eminently sensible, since its distribution is
> precisely
> that of a (temporal) adverb rather than that of an arbitrary noun
> phrase. We wouldn't want to consider "paint" as a ditransitive verb in
> the sentence "He painted his house last Sunday". I would expect a
> tagger
> that assigned "last Sunday" the same tag as "yesterday" to out-perform
> one that called it an adjective-noun sequence.

I appreciate Pete's point of view, but such a tagger will be "confused" every time it deals with NPs functioning as modifiers. If this were an aberration, then perhaps it would be best to call it an adverb and be done with it, but it's actually a rather common function for NPs. In the example sentence, there are many NPs that could stand in for 'last Sunday': next week, this morning, Labour Day weekend, etc. If these are all adverbs, then it certainly is a devilishly heterogeneous category.

And, yes, 'last Sunday' and 'yesterday' should both be assigned the same tag: NP, except that 'last Sunday' is a proper noun with an attributive adjective functioning as its modifier where 'yesterday' is a pronoun.

Of course, NPs don't just function as temporal modifiers in clauses; they function as modifiers in NPs (e.g., FACULTY office), PPs (TWO MILES down the road), VPs (she SUCKER punched me), and even in determiner phrases (e.g., MY many interests). They're positively promiscuous as modifiers, but many grammars want to deny this fact altogether and relegate them only to subject and object functions. Such denials seem likely to lead to inconsistent tagging results.

Moreover, the distribution of 'last Sunday' is by no means "precisely that of a (temporal) adverb." In the sentence "Last Sunday changed my life", it is hard to conceive of an adverb that might me able to stand in for it, though raising or a mention (v.s. use) could perhaps force a grammatical sentence out of something like "'quickly' changed my life."

Best, Brett


----------------------- Brett Reynolds English Language Centre Humber College Institute of Technology and Advanced Learning Toronto, Ontario, Canada brett.reynolds at humber.ca

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