My research has covered a broad range of topics in applied computational linguistics and natural language processing.  They include: lexical semantics; the resolution of ambiguity in text; the analysis of authors’ styles in literature and other text (including plagiarism detection and the detection of online sexual predators) and the preservation of an author’s style in machine translation; recovering from misunderstanding and non-understanding in human-computer communication; linguistic constraints on knowledge-representation systems; the problem of near-synonymy in lexical choice in language generation; applications of lexical chaining as an indicator of semantic distance in texts; detecting markers of Alzheimer's disease in language; determining ideology in political texts; and the identification of the native language of a second-language writer of English.  With colleagues in Canada, the U.K. and the Netherlands, I was a co-PI of a Digging Into Data grant on processing linked parliamentary data.


Current and recent research topics

Determing causes of death from verbal autopsies

Detecting Alzheimer’s disease, aphasia, and cognitive decline in writing and speech

Models of semantic distance

Lexical nuances of style and meaning

Discourse coherence and rhetorical parsing

Automatic discrimination of authorship, including the detection of plagiarism and sexual predation

Digitizing and analyzing Parliamentary proceedings

Resolving shell nouns

Theoretical issues of meaning and representation in computational linguistics

Argument mining; analyzing the framing of issues; determining a speaker's ideology

Computational analysis of literature


Some past projects

Medical question-answering at the point of care

Intelligent real-word spelling correction

Syntactic nuances of style and meaning

Finding and applying threads of meaning in documents

Discourse structure, rhetorical parsing, and text summarization

Support for collaborative writing

The repair of misunderstanding and non-understanding

Graeme Hirst

Professor of Computational Linguistics

University of Toronto, Department of Computer Science

Research