Eckhard Bick - VISL

Sources:
English:
EngCG: Karlsson et. al. (1995)
FDG: http://www.conexor.fi/fdg.html#1 (14.3.1999), by conexor
Portuguese: Bick (1996)
Swedish: http://huovinen.lingsoft.fi/doc/swecg/intro/stags.html (23.12.1998), by lingsoft
Norwegian: http://www.hf.uio.no/tekstlab/tagger.html (23.12.1998), by Janni Bonde Johannesen
Estonian: http://www.cl.ut.ee/ee/yllitised/first/kailimyyrisep.html (23.12.1998) by Kaili
Müürisep, University of Tartu
In their comparison between ENGCG and their newly developed FDG, Voutilainen
and Tapanainen (http://www.conexor.fi) report morphosyntactic success rates
(percentage of correct morphosyntactic labels present in the output) of 94.2-96.8%
for ENGCG and 96.4-97% for FDG, with an ambiguity rate of 11.3-13.7% for the
former, and 3.2-3.3% for the latter. The Portuguese parser compares favourably to
this, achieving about the same success rate as FDG (96.4-97.5) even with an
ambiguity rate close to zero.
For Estonian, Müürisep (1996), reports a syntactic error rate of 0.32%, but
with an ambiguity rate of 32% (1.47 tags per word), making a direct comparison
difficult.
On the morphological level, performance is evidently better than on the
syntactic level, for all CG systems. The “classic” ENGCG can be regarded as a base
line, with an error rate of only 0.3% at 3-7% disambiguation. For SWECG 1.0, a
Swedish Constraint Grammar (where no performance data on the syntactic level
could be obtained at the time of writing), morphological performance is about the
same as for English, with an error rate of 0.3%, at an ambiguity rate of 5%
(www.sics.se/ humle/ projects/ svensk/ projectPlan.html, by Mikael Eriksson, Björn Gambäck and
Scott McGlashan, accessed on 23.12.98). The Portuguese parser, by comparison, has an
error range between 0.3% and 1.2%, with 0% ambiguity.
With regard to the dependency performance of PALAVRAS, only a
comparison with FDG makes sense. To compile table (4), a 5000-word text chunk
was automatically analysed by a tree-generating version of PALAVRAS (the one
used internally in the VISL grammar teaching programs), producing vertical tree
output as in the example below (3).
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