This work reports the results of an enquiry on the concept of relevance and on relevance judgments carried out during the MIRA workshops activities in 1998/1999. Starting from a previous proposal , we present the multidimensional relevance space, a framework for describing the various kinds of relevance, which has been negotiated with experts belonging to the MIRA community. The relevance dimensions of information needs, information resources, and information use context are presented, and a three dimensional graphical representation of the framework is proposed. The differences between the original framework and the revised one, and the advantages of the latter, are discussed. Some implications of the framework for the design and evaluation of information access systems and their user interfaces are also derived and, finally, an exploratory study on the issue of agreement in relevance judgments, and its consequences for the design of multimedia test collections, are presented.