1 Introduction

Datawarehouses have become the most important trend in business information technology and represent one of the most interesting areas within the database industry (Chaudhuri and Dayal, 1997) as they provide relevant and precise information enabling the improvement of strategic decisions (Jarke et al., 2000) and as such the quality of the information that they contain must be guaranteed (English, 1996). In fact, a lack of quality can have disastrous consequences from both a technical (Celko, 1995) and organisational point of view loss of clients (Redman, 1996), important financial losses (Loshin, 2001) or discontent amongst employees (English, 1996).

The quality of the information of a datawarehouse is determined by the quality of the system itself as well as by the quality of the presentation of the data (see Fig. 1). Clearly it is important not only that the data of the datawarehouse correctly reflects the real world, but also that the data is interpreted correctly. As...