This paper presents a systemic view of collocation in order to explore how scientists optimally select and present information in abstracts. In a previous large scale study of 150 research articles (Gledhill 1995), collocational analysis revealed the key role of idiom in defining a norm of scientific writing and in the progressive textual creation of new scientific ideas (associated with the concept of logogenesis: Halliday and Martin (1993)). In order to deal with the analysis of textual genres it is necessary to conduct corpus analysis that is sensitive to the professional goals and practices in which a specific text type is couched. This article describes an approach to corpus analysis which marries the context- sensitive approach of genre analysis (Swales 1990) with the latest computational techniques for establishing global linguistic properties of text (Sinclair 1993). In particular, the notion of phraseology can be seen to operate at a level that incorporates the collocational properties of high frequency items with what has come to be known as 'terse text'.