ISSUES WITH PARTIALLY MATCHING FEATURE FUNCTIONS IN CONDITIONAL EXPONENTIAL MODELS

Carsten Elfers, Hartmut Messerschmidt, Otthein Herzog

2012

Abstract

Conditional Exponential Models (CEM) are effectively used in several machine learning approaches, e.g., in Conditional Random Fields. Their feature functions are typically either satisfied or not. This paper presents a way to use partially matching feature functions which are satisfied to some degree and corresponding issues while training. Using partially matching feature functions improves the inference accuracy in domains with sparse reference data and avoids overfitting. Unfortunately, the typically used Maximum Likelihood training includes some issues for using partially matching feature functions. In this context three problems (inequality of influence, unlimited weight boundaries and local optima in parameter space) with Improved Iterative Scaling (a popular training algorithm for Conditional Exponential Models) using such feature functions are stated and solved.

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Paper Citation


in Harvard Style

Elfers C., Messerschmidt H. and Herzog O. (2012). ISSUES WITH PARTIALLY MATCHING FEATURE FUNCTIONS IN CONDITIONAL EXPONENTIAL MODELS . In Proceedings of the 4th International Conference on Agents and Artificial Intelligence - Volume 1: SSML, (ICAART 2012) ISBN 978-989-8425-95-9, pages 571-578. DOI: 10.5220/0003855205710578

in Bibtex Style

@conference{ssml12,
author={Carsten Elfers and Hartmut Messerschmidt and Otthein Herzog},
title={ISSUES WITH PARTIALLY MATCHING FEATURE FUNCTIONS IN CONDITIONAL EXPONENTIAL MODELS},
booktitle={Proceedings of the 4th International Conference on Agents and Artificial Intelligence - Volume 1: SSML, (ICAART 2012)},
year={2012},
pages={571-578},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0003855205710578},
isbn={978-989-8425-95-9},
}


in EndNote Style

TY - CONF
JO - Proceedings of the 4th International Conference on Agents and Artificial Intelligence - Volume 1: SSML, (ICAART 2012)
TI - ISSUES WITH PARTIALLY MATCHING FEATURE FUNCTIONS IN CONDITIONAL EXPONENTIAL MODELS
SN - 978-989-8425-95-9
AU - Elfers C.
AU - Messerschmidt H.
AU - Herzog O.
PY - 2012
SP - 571
EP - 578
DO - 10.5220/0003855205710578