Quantile Encoder: Tackling High Cardinality Categorical Features in Regression Problems

Autor: Carlos Mougan, Oriol Pujol, David Masip, Jordi Nin
Rok vydání: 2021
Předmět:
Zdroj: Modeling Decisions for Artificial Intelligence ISBN: 9783030855284
MDAI
Lecture Notes in Computer Science
Lecture Notes in Computer Science-Modeling Decisions for Artificial Intelligence
ISSN: 0302-9743
1611-3349
DOI: 10.1007/978-3-030-85529-1_14
Popis: Regression problems have been widely studied in machine learning literature resulting in a plethora of regression models and performance measures. However, there are few techniques specially dedicated to solve the problem of how to incorporate categorical features to regression problems. Usually, categorical feature encoders are general enough to cover both classification and regression problems. This lack of specificity results in underperforming regression models. In this paper, we provide an in-depth analysis of how to tackle high cardinality categorical features with the quantile. Our proposal outperforms state-of-the-art encoders, including the traditional statistical mean target encoder, when considering the Mean Absolute Error, especially in the presence of long-tailed or skewed distributions. Besides, to deal with possible overfitting when there are categories with small support, our encoder benefits from additive smoothing. Finally, we describe how to expand the encoded values by creating a set of features with different quantiles. This expanded encoder provides a more informative output about the categorical feature in question, further boosting the performance of the regression model.
Databáze: OpenAIRE