Managing information in the form of text is the main concern of this thesis. In particular,we investigate text that is daily made available through the increasing use of e-mail. Wedescribe the design and implementation of a conceptual model,CAFE (CategorizationAssistant For E-mail). We also present the results of a case study and a survey that moti-vate the model.

The case study studies the effect of the computer screen on people’s structural build-up ofcategories for e-mail messages. Three different representations of categories are used:desktop, tree, and mind map. Cognitive science theories have served as an inspiration andmotivation for the study. The survey presents a selection of currently available e-mail cli-ents and the state-of-the-art and trends in e-mail management.

Our conceptual model provides support for organization, searching, and retrieval of infor-mation in e-mail. Three working modes are available for satisfying the user’s variousneeds in different situations: the Busy mode for intermittent usage at times of high stress,the Cool mode for continuous usage at the computer, and the Curious mode for sporadicusage when exploring and (re-)organizing messages when more time is at hand.

A prototype implementation has been developed. Each mode required using a different in-formation retrieval and filtering technique. Busy uses the text-based Naive Bayesian ma-chine learning algorithm, Cool uses common e-mail filtering rules, and Curious uses acombination of clustering techniques known asSCATTER/GATHER. Preliminary tests of theprototype have proved to be promising.