Insights into social phenomenon can be gleaned from trends and patterns in corpora of documents associated with that phenomenon. Recent years have witnessed the use of computational techniques, mostly based on keywords, to analyze large corpora for these purposes. In this paper, we extend these techniques to incorporate semantic features. We introduce Doris, an interactive exploration tool that combines semantic features with information retrieval techniques to enable exploration of document corpora corresponding to the social phenomenon. We discuss the semantic techniques and describe an implementation on a corpus of United States (US) presidential speeches. We illustrate, with examples, how the ability to combine syntactic and semantic features in a visualization helps researchers more easily gain insights into the underlying phenomenon.
This article discusses the extent to which methods normally associated with corpus linguistics can be effectively used by critical discourse analysts. Our research is based on the analysis of a 140-million-word corpus of British news articles about refugees, asylum seekers, immigrants and migrants (collectively RASIM). We discuss how processes such as collocation and concordance analysis were able to identify common categories of representation of RASIM as well as directing analysts to representative texts in order to carry out qualitative analysis. The article suggests a framework for adopting corpus approaches in critical discourse analysis.