#8044The base parser produces a set of candidate parses for each input sentence, with associatedprobabilities that define an initial ranking of these parses.
tech,8-12-J05-1003,ak
experiments in this article are on
<term>
natural language parsing ( NLP )
</term>
, the approach should be applicable
#8309Although the experiments in this article are onnatural language parsing ( NLP ), the approach should be applicable to many other NLP problems which are naturally framed as ranking tasks, for example, speech recognition, machine translation, or natural language generation.
tech,36-12-J05-1003,ak
ranking tasks
</term>
, for example ,
<term>
speech recognition
</term>
,
<term>
machine translation
</term>
#8337Although the experiments in this article are on natural language parsing (NLP), the approach should be applicable to many other NLP problems which are naturally framed as ranking tasks, for example,speech recognition, machine translation, or natural language generation.
other,4-7-J05-1003,ak
treebank
</term>
. The method combined the
<term>
log-likelihood under a baseline model
</term>
( that of Collins [ 1999 ] ) with
#8168The method combined thelog-likelihood under a baseline model (that of Collins [1999]) with evidence from an additional 500,000 features over parse trees that were not included in the original model.
other,11-2-J05-1003,ak
<term>
candidate parses
</term>
for each
<term>
input sentence
</term>
, with associated
<term>
probabilities
#8039The base parser produces a set of candidate parses for eachinput sentence, with associated probabilities that define an initial ranking of these parses.
other,30-12-J05-1003,ak
</term>
which are naturally framed as
<term>
ranking tasks
</term>
, for example ,
<term>
speech recognition
#8331Although the experiments in this article are on natural language parsing (NLP), the approach should be applicable to many other NLP problems which are naturally framed asranking tasks, for example, speech recognition, machine translation, or natural language generation.
other,16-9-J05-1003,ak
</term>
which takes advantage of the
<term>
sparsity
</term>
of the
<term>
feature space
</term>
in
#8242The article also introduces a new algorithm for the boosting approach which takes advantage of thesparsity of the feature space in the parsing data.
other,17-3-J05-1003,ak
additional
<term>
features
</term>
of the
<term>
tree
</term>
as evidence . The strength of our
#8071A second model then attempts to improve upon this initial ranking, using additional features of thetree as evidence.
other,23-7-J05-1003,ak
evidence from an additional 500,000
<term>
features
</term>
over
<term>
parse trees
</term>
that
#8187The method combined the log-likelihood under a baseline model (that of Collins [1999]) with evidence from an additional 500,000features over parse trees that were not included in the original model.
other,7-2-J05-1003,ak
base parser
</term>
produces a set of
<term>
candidate parses
</term>
for each
<term>
input sentence
</term>
#8035The base parser produces a set ofcandidate parses for each input sentence, with associated probabilities that define an initial ranking of these parses.
model,2-8-J05-1003,ak
original
<term>
model
</term>
. The new
<term>
model
</term>
achieved 89.75 %
<term>
F-measure
</term>
#8202The newmodel achieved 89.75% F-measure, a 13% relative decrease in F-measure error over the baseline model’s score of 88.2%.
other,26-4-J05-1003,ak
, without concerns about how these
<term>
features
</term>
interact or overlap and without the
#8101The strength of our approach is that it allows a tree to be represented as an arbitrary set of features, without concerns about how thesefeatures interact or overlap and without the need to define a derivation or a generative model which takes these features into account.
other,23-9-J05-1003,ak
the
<term>
feature space
</term>
in the
<term>
parsing data
</term>
. Experiments show significant efficiency
#8249The article also introduces a new algorithm for the boosting approach which takes advantage of the sparsity of the feature space in theparsing data.
tech,13-5-J05-1003,ak
reranking task
</term>
, based on the
<term>
boosting approach to ranking problems
</term>
described in Freund et al. ( 1998
#8137We introduce a new method for the reranking task, based on theboosting approach to ranking problems described in Freund et al. (1998).
other,25-7-J05-1003,ak
additional 500,000
<term>
features
</term>
over
<term>
parse trees
</term>
that were not included in the original
#8189The method combined the log-likelihood under a baseline model (that of Collins [1999]) with evidence from an additional 500,000 features overparse trees that were not included in the original model.
tech,1-2-J05-1003,ak
<term>
probabilistic parser
</term>
. The
<term>
base parser
</term>
produces a set of
<term>
candidate
#8029Thebase parser produces a set of candidate parses for each input sentence, with associated probabilities that define an initial ranking of these parses.
measure(ment),6-8-J05-1003,ak
<term>
model
</term>
achieved 89.75 %
<term>
F-measure
</term>
, a 13 % relative decrease in
<term>
#8206The new model achieved 89.75%F-measure, a 13% relative decrease in F-measure error over the baseline model’s score of 88.2%.
model,25-11-J05-1003,ak
feature selection methods
</term>
within
<term>
log-linear ( maximum-entropy ) models
</term>
. Although the experiments in this
#8295We argue that the method is an appealing alternative—in terms of both simplicity and efficiency—to work on feature selection methods withinlog-linear ( maximum-entropy ) models.
other,10-4-J05-1003,ak
of our approach is that it allows a
<term>
tree
</term>
to be represented as an arbitrary
#8085The strength of our approach is that it allows atree to be represented as an arbitrary set of features, without concerns about how these features interact or overlap and without the need to define a derivation or a generative model which takes these features into account.
other,19-9-J05-1003,ak
of the
<term>
sparsity
</term>
of the
<term>
feature space
</term>
in the
<term>
parsing data
</term>
.
#8245The article also introduces a new algorithm for the boosting approach which takes advantage of the sparsity of thefeature space in the parsing data.