In this paper, we perform an error analysis on human and LLM annotation data from the recent GUMBridge corpus for varieties of bridging anaphora. We explore the distribution of precision and recall errors made by annotators and how that distribution correlates with bridging subtypes. We find that while LLMs perform substantially worse than human annotators, they are more balanced in their precision and recall scores than humans, whose performance strongly favors precision. With regard to subtypes, we find that comparison and meronomy relations are easier to reliably annotate than the more broadly construed entity relations for both human and LLM annotators, but that LLM errors are more distributed across subtypes than human errors. Analyzing these results, we provide insights for future annotation projects on bridging anaphora.

Despite a long tradition of work on extractive summarization, which by nature aims to recover the most important propositions in a text, little work has been done on operationalizing graded proposition salience in naturally occurring data. In this paper, we adopt graded summarization-based salience as a metric from previous work on Salient Entity Extraction (SEE) and adapt it to quantify proposition salience. We define the annotation task, apply it to a small multi-genre dataset, evaluate agreement and carry out a preliminary study of the relationship between our metric and notions of discourse unit centrality in discourse parsing following Rhetorical Structure Theory (RST).

In this paper, we present a descriptive corpus analysis of bridging anaphora across 16 genres of English, leveraging the multi-genre GUMBridge corpus for varieties of bridging anaphora. We begin our investigation by examining the distribution of bridging instances by sub-varieties and across genres, finding that spoken genres have less bridging instances than written ones. We then investigate the linguistic environments of bridging anaphora and their corresponding associative antecedents in the underlying data of the corpus, examining both categorical features (entity type, part of speech, syntactic dependency relations) and numeric features (mention length, cluster size, salience, and distance between the bridging anaphor and antecedent). We find bridging anaphora have a tendency to be shorter and are more often definite, and bridging antecedents show a tendency to be more salient than other entities. Finally, we analyze how several of the numeric features of bridging environments vary by genre, finding consistent patterns across genres for observed trends in the environments of bridging anaphora and antecedents.