TY - CHAP

T1 - Entropy-guided feature generation for structured learning of Portuguese dependency parsing

AU - Fernandes, Eraldo R.

AU - Milidiú, Ruy L.

N1 - Conference code: 10

PY - 2012

Y1 - 2012

N2 - Feature generation is a difficult, yet highly necessary, subtask of machine learning modeling. Usually, it is partially solved by a domain expert that generates complex and discriminative feature templates by conjoining the available basic features. This is a limited and expensive way to obtain feature templates and is recognized as a modeling bottleneck. In this work, we propose an automatic method to generate feature templates for structured learning algorithms. The method receives as input the training dataset with basic features and produces a set of feature templates by conjoining basic features that are highly discriminative together. We denote this method entropy guided since it is based on the conditional entropy of local decision variables given the feature values. We illustrate our approach on the Portuguese dependency parsing task and report on experiments with the Bosque corpus. We show that the entropy-guided templates outperform the manually built templates used by MSTParser, which was the best performing system on the Bosque corpus up to now. Furthermore, our approach allows an effortless inclusion of two new basic features that automatically generate additional templates. As a result, our system achieves a per-token accuracy of 92.66%, what represents a reduction by more than 15% on the previous smallest error rate for Portuguese dependency parsing.

AB - Feature generation is a difficult, yet highly necessary, subtask of machine learning modeling. Usually, it is partially solved by a domain expert that generates complex and discriminative feature templates by conjoining the available basic features. This is a limited and expensive way to obtain feature templates and is recognized as a modeling bottleneck. In this work, we propose an automatic method to generate feature templates for structured learning algorithms. The method receives as input the training dataset with basic features and produces a set of feature templates by conjoining basic features that are highly discriminative together. We denote this method entropy guided since it is based on the conditional entropy of local decision variables given the feature values. We illustrate our approach on the Portuguese dependency parsing task and report on experiments with the Bosque corpus. We show that the entropy-guided templates outperform the manually built templates used by MSTParser, which was the best performing system on the Bosque corpus up to now. Furthermore, our approach allows an effortless inclusion of two new basic features that automatically generate additional templates. As a result, our system achieves a per-token accuracy of 92.66%, what represents a reduction by more than 15% on the previous smallest error rate for Portuguese dependency parsing.

KW - dependency parsing

KW - entropy-guided feature generation

KW - machine learning

KW - structured learning

KW - Informatics

KW - Business informatics

UR - http://www.scopus.com/inward/record.url?scp=84858599304&partnerID=8YFLogxK

UR - https://d-nb.info/1019948167

U2 - 10.1007/978-3-642-28885-2_17

DO - 10.1007/978-3-642-28885-2_17

M3 - Article in conference proceedings

AN - SCOPUS:84858599304

SN - 978-3-642-28884-5

T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

SP - 146

EP - 156

BT - Computational Processing of the Portuguese Language

A2 - Caseli, Helena

A2 - Villavicencio, Aline

A2 - Teixeira, Antonio

A2 - Perdigao, Fernando

PB - Springer Verlag

CY - Berlin, Heidelberg

T2 - International Conference on Computational Processing of Portuguese

Y2 - 17 April 2012 through 20 April 2012

ER -