Stylistic variation within genre conventions in the Enron email corpus: developing a textsensitive methodology for authorship research

Abstract

Over recent years there has been much theoretical discussion regarding idiolect and its usefulness in forensic authorship analysis. This article, drawing on email data from the former American energy company Enron, offers an empirical investigation into identifying individuals’ idiolects through analysing author distinctive variation within two conventions of the email genre – greetings and farewells. The first part of a two-stage analysis identifies a number of forms which distinguish between authors in a four-author corpus. Using likelihood ratios, the second stage of analysis finds that some of the greeting and farewell forms identified, and combinations of forms, remain distinctive and individuating of their author when tested against the 126-author ‘Enron Sent Email Author Reference Corpus’, and highlights the diagnostic power of less frequent variants. The results from this article offer both theoretical and methodological contributions as well as a baseline of population results for forensic authorship casework involving emails.