Linguistic Variation in Research Articles investigates the linguistic characteristics of academic research articles, going beyond a traditional analysis of the generically-defined research article to take into account varied realizations of research articles within and across disciplines. It combines corpus-based analyses of 70+ linguistic features with analyses of the situational, or non-linguistic, characteristics of the Academic Journal Registers Corpus: 270 research articles from 6 diverse disciplines (philosophy, history, political science, applied linguistics, biology, physics) and representing three sub-registers (theoretical, quantitative, and qualitative research). Comprehensive analyses include a lexical/grammatical survey, an exploration of structural complexity, and a Multi-Dimensional analysis, all interpreted relative to the situational analysis of the corpus. The finding that linguistic variation in research articles does not occur along a single parameter like discipline is discussed relative to our understanding of disciplinary practices, the multidimensional nature of variation in research articles, and resulting methodological considerations for corpus studies of disciplinary writing.