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From Benson Margulies <ben...@basistech.com>
Subject Re: PositionLengthAttribute
Date Sat, 07 Sep 2013 11:44:01 GMT
In Japanese, compounds are just decompositions of the input string. In
other languages, compounds can manufacture entire tokens from thin
air. In those cases, it's something of a question how to decide on the
offsets. I think that you're right, eventually, insofar as there's
some offset in the original that might as well be blamed for any given
component.


On Fri, Sep 6, 2013 at 9:37 PM, Robert Muir <rcmuir@gmail.com> wrote:
> On Fri, Sep 6, 2013 at 9:32 PM, Benson Margulies <benson@basistech.com> wrote:
>> On Fri, Sep 6, 2013 at 9:28 PM, Robert Muir <rcmuir@gmail.com> wrote:
>>> its the latter. the way its designed to work i think is illustrated
>>> best in kuromoji analyzer where it heuristically decompounds nouns:
>>>
>>> if it decompounds ABCD into AB + CD, then the tokens are AB and CD.
>>> these both have posinc=1.
>>> however (to compensate for precision issue you mentioned on the other
>>> thread), it keeps the full compound as a synonym too (there are some
>>> papers benchmarking this approach for decompounding, just think of IDF
>>> etc sorting things out).
>>> so that ABCD synonym has position increment 0, and it "sits" at the
>>> same position as the first token (AB). but it has positionLength=2,
>>> which basically keeps the information in the chain that this "synonym"
>>> spans across both AB and CD.
>>>
>>> so the output is like this: AB(posinc=1,posLength=1),
>>> ABCD(posinc=0,posLength=2), CD(posinc=1, posLength=1)
>>
>> I suppose this works best if you actually know the offsets of the
>> pieces. In disassembling German, this is not always straightforward.
>>
>
> i dont really see how it has anything to do with natural languages?
> its just the way you represent the compound components in the
> tokenstream.
>
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