A system for evaluating information. The system defines a set of properties and one or more values for each property and then assigns property-value combinations to items of information and to profiles. Information is then evaluated by determining how the property-value combinations assigned to the items of information match those assigned to a profile. Assignments of property-value combinations have ratings and validities associated with them. In assignments to information items, the rating represents the relevance of the information item to the property-value pair; in assignments to profiles, it represents the relevance of the property-value pair to the profile. The validity for an assignment indicates a judgment concerning the strength of the assignment. The system further defines relationships between property-value combinations. When a property-value combination in a relationship is assigned, so are the related property-value combinations. One application for the system is in producing output that is personalized for a recipient. The recipient is represented by a profile. The output is a hierarchy of information items, and in making the output the system chooses among alternatives on the basis of the property-value assignments to the information items and the recipient's profile. Choice of components begins at the bottom of the hierarchy, with the scores of choices at lower levels affecting the choices at higher levels. Another use of the system is in evaluating feedback information items received from the recipient. Also disclosed are graphical user interfaces for defining properties and values and assigning properties and values to information items and profiles.