Transfer Learning from LDA to BiLSTM-CNN for Offensive Language Detection in Twitter
This work addresses offensive language detection for German social media users, presenting an incremental improvement through transfer learning.
The paper tackled offensive language detection in German Twitter by testing transfer learning strategies on a BiLSTM-CNN model, finding that unsupervised topic clustering with user information yielded the best performance improvements.
We investigate different strategies for automatic offensive language classification on German Twitter data. For this, we employ a sequentially combined BiLSTM-CNN neural network. Based on this model, three transfer learning tasks to improve the classification performance with background knowledge are tested. We compare 1. Supervised category transfer: social media data annotated with near-offensive language categories, 2. Weakly-supervised category transfer: tweets annotated with emojis they contain, 3. Unsupervised category transfer: tweets annotated with topic clusters obtained by Latent Dirichlet Allocation (LDA). Further, we investigate the effect of three different strategies to mitigate negative effects of 'catastrophic forgetting' during transfer learning. Our results indicate that transfer learning in general improves offensive language detection. Best results are achieved from pre-training our model on the unsupervised topic clustering of tweets in combination with thematic user cluster information.