Marie-Catherine de Marneffe

Finding Contradictions in Text

Detecting conflicting statements is a foundational text understanding task with applications in information analysis and updating. I propose an appropriate definition of contradiction for natural language processing (NLP) tasks and develop available corpora using this definition, from which I construct a typology of contradictions. I demonstrate that a system for contradiction needs to make more fine- grained and subtle distinctions than the more common systems for entailment. In particular, I argue for the centrality of event coreference and therefore incorporate such a component based on topicality. I present the first detailed breakdown of performance on this task. Detecting some types of contradiction requires deeper inferential paths than the system is capable of, but its achieves good performance on other types such as those arising from negation and antonymy.