DFKI-NLP is a Natural Language Processing group of researchers, software engineers and students at the Berlin office of the German Research Center for Artificial Intelligence (DFKI) working on basic and applied research in areas covering, among others, information extraction, knowledge base population, dialogue, sentiment analysis, and summarization. We are particularly interested in core research on learning in low-resource settings, reasoning over larger contexts, and continual learning. We strive for a deeper understanding of human language and thinking, with the goal of developing novel methods for processing and generating human language text, speech, and knowledge. An important part of our work is the creation of corpora, the evaluation of NLP datasets and tasks, and the explainability of (neural) models.
Our group forms a part of DFKI’s Speech and Language Technology department led by Prof. Sebastian Möller, and closely collaborates with e.g. the Technische Universität Berlin, DFKI’s Language Technology and Multilinguality department and DFKI’s Intelligent Analytics for Massive Data group.
One paper from DFKI-NLP researchers has been accepted for publication at KONVENS 2023, the 19th German Conference on Natural Language Processing. The conference will take place in Ingolstadt, Germany, from Sep 18th to Sep 22nd, 2023.
Five papers from DFKI-NLP researchers have been accepted for publication at ACL 2023, the 61st Annual Meeting of the Association for Computational Linguistics. The conference is planned to be a hybrid meeting and will take place in Toronto, Canada, from Jul 9th through July 14th, 2023.
Two papers from DFKI-NLP authors have been accepted for publication at EMNLP 2022, the 2022 Conference on Empirical Methods in Natural Language Processing. The conference is planned to be a hybrid meeting and will take place in Abu Dhabi, from Dec 7th to Dec 11th, 2022.
One paper from DFKI-NLP authors has been accepted for publication at the Workshop on Information Extraction from Scientific Publications (WIESP). The workshop will be held at AACL-IJCNLP 2022, the 2nd Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics and the 12th International Joint Conference on Natural Language Processing, which will take place as an online-only event from Nov.
One paper from DFKI-NLP authors has been accepted for publication at JCDL 2022, the 22nd ACM/IEEE Joint Conference on Digital Libraries. The conference is planned to be a hybrid meeting and will take place in Cologne, Germany, from June 20th through June 24th, 2022.
Factuality can play an important role when automatically processing clinical text, as it makes a difference if particular symptoms are explicitly not present, possibly present, not mentioned, or affirmed. In most cases, a sufficient number of examples is necessary to handle such phenomena in a supervised machine learning setting. However, as clinical text might contain sensitive information, data cannot be easily shared. In the context of factuality detection, this work presents a simple solution using machine translation to translate English data to German to train a transformer-based factuality detection model.
Past work in natural language processing interpretability focused mainly on popular classification tasks while largely overlooking generation settings, partly due to a lack of dedicated tools. In this work, we introduce Inseq, a Python library to democratize access to interpretability analyses of sequence generation models. Inseq enables intuitive and optimized extraction of models' internal information and feature importance scores for popular decoder-only and encoder-decoder Transformers architectures. We showcase its potential by adopting it to highlight gender biases in machine translation models and locate factual knowledge inside GPT-2. Thanks to its extensible interface supporting cutting-edge techniques such as contrastive feature attribution, Inseq can drive future advances in explainable natural language generation, centralizing good practices and enabling fair and reproducible model evaluations.
State-of-the-art techniques common to low resource Machine Translation (MT) are applied to improve MT of spoken language text to Sign Language (SL) glosses. In our experiments, we improve the performance of the transformer-based models via (1) data augmentation, (2) semi-supervised Neural Machine Translation (NMT), (3) transfer learning and (4) multilingual NMT. The proposed methods are implemented progressively on two German SL corpora containing gloss annotations. Multilingual NMT combined with data augmentation appear to be the most successful setting, yielding statistically significant improvements as measured by three automatic metrics (up to over 6 points BLEU), and confirmed via human evaluation. Our best setting outperforms all previous work that report on the same test-set and is also confirmed on a corpus of the American Sign Language (ASL).
Saliency maps can explain a neural model’s predictions by identifying important input features. They are difficult to interpret for laypeople, especially for instances with many features. In order to make them more accessible, we formalize the underexplored task of translating saliency maps into natural language and compare methods that address two key challenges of this approach – what and how to verbalize. In both automatic and human evaluation setups, using token-level attributions from text classification tasks, we compare two novel methods (search-based and instruction-based verbalizations) against conventional feature importance representations (heatmap visualizations and extractive rationales), measuring simulatability, faithfulness, helpfulness and ease of understanding. Instructing GPT-3.5 to generate saliency map verbalizations yields plausible explanations which include associations, abstractive summarization and commonsense reasoning, achieving by far the highest human ratings, but they are not faithfully capturing numeric information and are inconsistent in their interpretation of the task. In comparison, our search-based, model-free verbalization approach efficiently completes templated verbalizations, is faithful by design, but falls short in helpfulness and simulatability. Our results suggest that saliency map verbalization makes feature attribution explanations more comprehensible and less cognitively challenging to humans than conventional representations.
Most Transformer language models are primarily pretrained on English text, limiting their use for other languages. As the model sizes grow, the performance gap between English and other languages with fewer compute and data resources increases even further. Consequently, more resource-efficient training methods are needed to bridge the gap for languages with fewer resources available. To address this problem, we introduce a cross-lingual and progressive transfer learning approach, called CLP-Transfer, that transfers models from a source language, for which pretrained models are publicly available, like English, to a new target language. As opposed to prior work, which focused on the cross-lingual transfer between two languages, we extend the transfer to the model size. Given a pretrained model in a source language, we aim for a same-sized model in a target language. Instead of training a model from scratch, we exploit a smaller model that is in the target language but requires much fewer resources. Both small and source models are then used to initialize the token embeddings of the larger model based on the overlapping vocabulary of the source and target language. All remaining weights are reused from the model in the source language. This approach outperforms the sole cross-lingual transfer and can save up to 80% of the training steps compared to the random initialization.