Knowledge is central to the modern economy and society. Indeed, the knowledge society has transformed
the concept of knowledge and is more and more aware of the need to overcome the lack of knowledge when has to
make options or address its problems and dilemmas. One`s knowledge is less based on exact facts and more on
hypotheses, perceptions or indications. Even when we use new computational artefacts and novel methodologies for
problem solving, like the use of Group Decision Support Systems (GDSS), the question of incomplete information is
in most of the situations marginalized. On the other hand, common sense tells us that when a decision is made it is
impossible to have a perception of all the information involved and the nature of its intrinsic quality. Therefore,
something has to be made in terms of the information available and the process of its evaluation. It is under this
framework that a Multi-valued Extended Logic Programming language will be used for knowledge representation
and reasoning, leading to a model that embodies the Quality-of-Information (QoI) and its quantification, along the
several stages of the decision making process. In this way it is possible to provide a measure of the value of the QoI
that supports the decision itself. This model will be here presented in the context of a GDSS for VirtualECare, a
system aimed at sustaining online healthcare services