APEACH: Attacking Pejorative Expressions with Analysis on Crowd-Generated Hate Speech Evaluation Datasets

Detecting toxic or pejorative expressions in online communities has become one of the main concerns for preventing the users' mental harm. This led to the development of large-scale hate speech detection datasets of various domains, which are mainly built upon web-crawled texts with labels by crowd workers. However, for languages other than English, researchers might have to rely on only a small-sized corpus due to the lack of data-driven research of hate speech detection. This sometimes misleads the evaluation of prevalently used pretrained language models (PLMs) such as BERT, given that PLMs often share the domain of pretraining corpus with the evaluation set, resulting in over-representation of the detection performance. Also, the scope of pejorative expressions might be restricted if the dataset is built on a single domain text. To alleviate the above problems in Korean hate speech detection, we propose APEACH,a method that allows the collection of hate speech generated by unspecified users. By controlling the crowd-generation of hate speech and adding only a minimum post-labeling, we create a corpus that enables the generalizable and fair evaluation of hate speech detection regarding text domain and topic. We Compare our outcome with prior work on an annotation-based toxic news comment dataset using publicly available PLMs. We check that our dataset is less sensitive to the lexical overlap between the evaluation set and pretraining corpus of PLMs, showing that it helps mitigate the unexpected under/over-representation of model performance. We distribute our dataset publicly online to further facilitate the general-domain hate speech detection in Korean.