Web portals are currently being used on an ever-increasing basis as a source of data to assist in users' daily tasks. However, not all web portals offer data with the same level of quality. It is therefore fundamental to identify which quality characteristics affect the data. Moreover, data quality needs depend on the type of user, and the importance that different users place on each data quality characteristic is therefore different. Bearing this in mind, we first present a data quality model for web portals which identifies four categories: intrinsic, contextual, representational and operational. In this paper, we focus on studying the intrinsic and contextual categories from the perspective of users with university studies. More specifically, we establish the preferences of users with regard to the data quality characteristics studied, and discover whether any differences exist according to their gender and age range. Copyright © 2013 Inderscience Enterprises Ltd.