Are We Really Making Much Progress in Text Classification? A Comparative Review

This study reviews and compares methods for single-label and multi-label text classification, categorized into bag-of-words, sequence-based, graph-based, and hierarchical methods. The comparison aggregates results from the literature over five single-label and seven multi-label datasets and complements them with new experiments. The findings reveal that all recently proposed graph-based and hierarchy-based methods fail to outperform pre-trained language models and sometimes perform worse than standard machine learning methods like a multilayer perceptron on a bag-of-words. To assess the true scientific progress in text classification, future work should thoroughly test against strong bag-of-words baselines and state-of-the-art pre-trained language models.