Sebastian Reimann


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Metaphors in Online Religious Communication: A Detailed Dataset and Cross-Genre Metaphor Detection
Sebastian Reimann | Tatjana Scheffler
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)

We present the first dataset of fine-grained metaphor annotations for texts from online religious communication, where figurative language plays a particularly important role. In addition to binary labels, metaphors are annotated for deliberateness, that is, whether they are communicated explicitly as metaphors, and we provide indicators for such deliberate use. We further show that cross-genre transfer metaphor detection (from the widely used VUA corpus to our Reddit data) leads to a drop in performance due to the shift in topic and metaphors from source domains that did not occur in the training data. We solve this issue by adding a small amount of in-genre data in fine-tuning, leading to notable performance increases of more than 5 points in F1. Moreover, religious communication has the tendency for extended metaphorical comparisons, which are problematic for current metaphor detection systems. Adding in-genre data had slightly positive effects but we argue that to solve this, architectures that consider larger spans of context are necessary.

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When is a Metaphor Actually Novel? Annotating Metaphor Novelty in the Context of Automatic Metaphor Detection
Sebastian Reimann | Tatjana Scheffler
Proceedings of The 18th Linguistic Annotation Workshop (LAW-XVIII)

We present an in-depth analysis of metaphor novelty, a relatively overlooked phenomenon in NLP. Novel metaphors have been analyzed via scores derived from crowdsourcing in NLP, while in theoretical work they are often defined by comparison to senses in dictionary entries. We reannotate metaphorically used words in the large VU Amsterdam Metaphor Corpus based on whether their metaphoric meaning is present in the dictionary. Based on this, we find that perceived metaphor novelty often clash with the dictionary based definition. We use the new labels to evaluate the performance of state-of-the-art language models for automatic metaphor detection and notice that novel metaphors according to our dictionary-based definition are easier to identify than novel metaphors according to crowd-sourced novelty scores. In a subsequent analysis, we study the correlation between high novelty scores and word frequencies in the pretraining and finetuning corpora, as well as potential problems with rare words for pre-trained language models. In line with previous works, we find a negative correlation between word frequency in the training data and novelty scores and we link these aspects to problems with the tokenization of BERT and RoBERTa.


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Cause and Effect in Governmental Reports: Two Data Sets for Causality Detection in Swedish
Luise Dürlich | Sebastian Reimann | Gustav Finnveden | Joakim Nivre | Sara Stymne
Proceedings of the LREC 2022 workshop on Natural Language Processing for Political Sciences

Causality detection is the task of extracting information about causal relations from text. It is an important task for different types of document analysis, including political impact assessment. We present two new data sets for causality detection in Swedish. The first data set is annotated with binary relevance judgments, indicating whether a sentence contains causality information or not. In the second data set, sentence pairs are ranked for relevance with respect to a causality query, containing a specific hypothesized cause and/or effect. Both data sets are carefully curated and mainly intended for use as test data. We describe the data sets and their annotation, including detailed annotation guidelines. In addition, we present pilot experiments on cross-lingual zero-shot and few-shot causality detection, using training data from English and German.


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Examining the Effects of Preprocessing on the Detection of Offensive Language in German Tweets
Sebastian Reimann | Daniel Dakota
Proceedings of the 17th Conference on Natural Language Processing (KONVENS 2021)