The purpose of the study was to investigate and describe the way in which people organise documents in their offices. Eight university faculty members were asked to describe their own offices in terms of the organisation of documents. Each respondent was also asked to sort a typical day's mail. Following the data analysis, four of the eight respondents were interviewed again, at which time the researcher used the results of the analysis as a guide and tried to sort and classify each respondent's mail as he or she might have. An inductively created content analysis of the data was performed and the results suggest that the criteria or factors that people take into account when classifying documents consist not only of document factors (such as the document's topic or form) but also, to a very important degree, of situational factors (such as the use to which the document is to be put). In addition, it was shown that people are able to articulate the process by which classification decisions were made, and the data produced by this articulation lend themselves to analysis at a level which can yield genera! rules about the behaviour. One implication of this study is that, in designing systems for organising documents, it might be advantageous to explore ways of modelling typical contexts of document use, since these seem to be very important in classification decisions made within personal information environments.