A Treebank-based Investigation of IPP-triggering Verbs in Dutch

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Unlabelled attachment
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no-sv, with words
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no-sv, no words
no-da, with words
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no-da, no words
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no skyline
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Figure 4: Learning curves for parsers using the Basic strategy
3.4 Conversion
As outlined in Section 2 there are a number of differences in terms of annotation
between our three corpora, in particular between the DDT and Talbanken/NDT.
In this section we present a set of more specific conversion procedures we use
to move our source corpora closer to the target corpus. Previous work in crosslingual
parser adaptation (Zeman and Resnik [12], Søgaard [9]) has considered
only unlabelled parsing, but as we will see in Section 3.4.3, it is entirely possible
to make a labelling parser.
3.4.1 Part-of-speech conversion
Until now, only the bare minimum of conversion and mapping has been applied
to the source corpora. But many of the differences in annotation strategy between
the source and target corpora are quite simple and easy to recover, and given the
close connection between the languages, it is not hard to do a more targeted PoS
tag mapping than what interset provides.
Specifically, we can convert both Talbanken and DDT’s PoS tagsets into the
tagset used by the NDT. For the most part, this is a simple matter of writing down a
look-up table mapping the tags in the source tagset to the corresponding tag in the
target tagset. Roughly 90% of both the Swedish and Danish tags can be converted
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