Most judicial decisions involve the interpretation of legal texts. As such, judicial opinions use language as the medium to comment on or draw attention to other language (for example, through definitions and hypotheticals about the meaning of a term from a statute). Language used this way is called metalanguage. Focusing on the U.S. Supreme Court, we view metalanguage as reflective of justices’ interpretive processes, bearing on current debates and theories about textualism in law and political science. As a step towards large-scale metalinguistic analysis with NLP, we identify 9 categories prominent in metalinguistic discussions, including key terms, definitions, and different kinds of sources. We annotate these concepts in a corpus of U.S. Supreme Court opinions. Our analysis of the corpus reveals high interannotator agreement, frequent use of quotes and sources, and several notable frequency differences between majority, concurring, and dissenting opinions. We observe fewer instances than expected of several legal interpretive categories. We discuss some of the challenges in developing the annotation schema and applying it and provide recommendations for how this corpus can be used for broader analyses.

In lexical semantics, full-sentence segmentation and segment labeling of various phenomena are generally treated separately, despite their interdependence. We hypothesize that a unified lexical semantic recognition task is an effective way to encapsulate previously disparate styles of annotation, including multiword expression identification / classification and supersense tagging. Using the STREUSLE corpus, we train a neural CRF sequence tagger and evaluate its performance along various axes of annotation. As the label set generalizes that of previous tasks (PARSEME, DiMSUM), we additionally evaluate how well the model generalizes to those test sets, finding that it approaches or surpasses existing models despite training only on STREUSLE. Our work also establishes baseline models and evaluation metrics for integrated and accurate modeling of lexical semantics, facilitating future work in this area.

For interpreting the behavior of a probabilistic model, it is useful to measure a model’s calibration—the extent to which it produces reliable confidence scores. We address the open problem of calibration for tagging models with sparse tagsets, and recommend strategies to measure and reduce calibration error (CE) in such models. We show that several post-hoc recalibration techniques all reduce calibration error across the marginal distribution for two existing sequence taggers. Moreover, we propose tag frequency grouping (TFG) as a way to measure calibration error in different frequency bands. Further, recalibrating each group separately promotes a more equitable reduction of calibration error across the tag frequency spectrum.

This paper presents our systems for SemEval 2020 Shared Task 11: Detection of Propaganda Techniques in News Articles. We participate in both the span identification and technique classification subtasks and report on experiments using different BERT-based models along with handcrafted features. Our models perform well above the baselines for both tasks, and we contribute ablation studies and discussion of our results to dissect the effectiveness of different features and techniques with the goal of aiding future studies in propaganda detection.

We present the Prepositions Annotated with Supsersense Tags in Reddit International English (“PASTRIE”) corpus, a new dataset containing manually annotated preposition supersenses of English data from presumed speakers of four L1s: English, French, German, and Spanish. The annotations are comprehensive, covering all preposition types and tokens in the sample. Along with the corpus, we provide analysis of distributional patterns across the included L1s and a discussion of the influence of L1s on L2 preposition choice.