Sentence Meta-Embeddings for Unsupervised Semantic Textual Similarity

We address the task of unsupervised Seman- tic Textual Similarity (STS) by ensembling di- verse pre-trained sentence encoders into sen- tence meta-embeddings. We apply, extend and evaluate different meta-embedding meth- ods from the word embedding literature at the sentence level, including dimensionality re- duction (Yin and Schu ̈tze, 2016), generalized Canonical Correlation Analysis (Rastogi et al., 2015) and cross-view auto-encoders (Bolle- gala and Bao, 2018). Our sentence meta- embeddings set a new unsupervised State of The Art (SoTA) on the STS Benchmark and on the STS12–STS16 datasets, with gains of be- tween 3.7% and 6.4% Pearson’s r over single- source systems

Neural architectures for open-type relation argument extraction

In this work, we focus on the task of open-type relation argument extraction (ORAE): given a corpus, a query entity Q, and a knowledge base relation (e.g., “Q authored notable work with title X”), the model has to extract an argument of non-standard entity type (entities that cannot be extracted by a standard named entity tagger, for example, X: the title of a book or a work of art) from the corpus. We develop and compare a wide range of neural models for this task yielding large improvements over a strong baseline obtained with a neural question answering system. The impact of different sentence encoding architectures and answer extraction methods is systematically compared. An encoder based on gated recurrent units combined with a conditional random fields tagger yields the best results. We release a data set to train and evaluate ORAE, based on Wikidata and obtained by distant supervision

Evaluating neural network explanation methods using hybrid documents and morphosyntactic agreement

The behavior of deep neural networks (DNNs) is hard to understand. This makes it necessary to explore post hoc explanation methods. We conduct the first comprehensive evaluation of explanation methods for NLP. To this end, we design two novel evaluation paradigms that cover two important classes of NLP problems: small context and large context problems. Both paradigms require no manual annotation and are therefore broadly applicable.We also introduce LIMSSE, an explanation method inspired by LIME that is designed for NLP. We show empirically that LIMSSE, LRP and DeepLIFT are the mosteffective explanation methods and recommend them for explaining DNNs in NLP

Data Centric Domain Adaptation for Historical Text with OCR Errors

We propose new methods for in-domain and cross-domain Named Entity Recognition (NER) on historical data for Dutch and French. For the cross-domain case, we address domain shift by integrating unsupervised in-domain data via contextualized string embeddings; and OCR errors by injecting synthetic OCR errors into the source domain and address data centric domain adaptation. We propose a general approach to imitate OCR errors in arbitrary input data. Our cross-domain as well as our in-domain results outperform several strong baselines and establish state-of-the-art results. We publish preprocessed versions of the French and Dutch Europeana NER corpora