A benchmark of categorical encoders for binary classification
This work addresses a methodological gap for researchers and practitioners in machine learning by providing a more reliable benchmark, though it is incremental as it builds on prior studies.
The authors tackled the problem of inconsistent and limited benchmarks for categorical encoders in binary classification by conducting the most comprehensive benchmark to date, evaluating 32 encoder configurations across 50 datasets and 36 experimental factor combinations, revealing that dataset selection, experimental factors, and aggregation strategies significantly influence conclusions.
Categorical encoders transform categorical features into numerical representations that are indispensable for a wide range of machine learning models. Existing encoder benchmark studies lack generalizability because of their limited choice of (1) encoders, (2) experimental factors, and (3) datasets. Additionally, inconsistencies arise from the adoption of varying aggregation strategies. This paper is the most comprehensive benchmark of categorical encoders to date, including an extensive evaluation of 32 configurations of encoders from diverse families, with 36 combinations of experimental factors, and on 50 datasets. The study shows the profound influence of dataset selection, experimental factors, and aggregation strategies on the benchmark's conclusions -- aspects disregarded in previous encoder benchmarks.