Applying Transfer Learning to German Metaphor Prediction

AbstractThis paper presents results in transfer-learning metaphor recognition in German. Starting from an English language corpus annotated for metaphor at the sentence level, and its machine-translation to German, we annotate 1000 sentences of the German part to use it as a Gold standard for two different metaphor prediction setups: i) a sequence labeling set-up (on the token-level), and ii) a classification (based on sentences) setup. We test two transfer leaning approaches: i) a group of transformer models, and ii) a technique that utilizes bilingual embeddings together with an RNN classifier. We find out that the transformer models do moderately in a zero-shot scenario (up to 61% F1 for classification) and the embeddings approaches do not even beat the guessing baseline (36% F1 for classification). We use our Gold data to fine-tune the classification tasks on target-language data achieving up to 90% F1 with both, the multilingual BERT and the bilingual embeddings. We also publish the annotated bilingual corpus.