Searching information in large and complex distributed information systems: balance between implicit and explicit acquisition of the user model

The knowledge about users acquired and formalised through a model may be used in more than one way in an interactive intelligent system. At the higher level, these models may be used for recognition and interpretation of information about the user's behaviour, to provide him with help facilities and a set of useful information. Literature mainly proposes two different strategies devoted to the acquisition of the user models; that is the implicit acquisition and the explicit acquisition. Both the previously introduced approaches are able to satisfy acquisition needs. In particular, this paper proposes an integrated perspective of the two previously introduced approaches and discusses the balance between implicit and explicit acquisition taking into account the user behaviour. The previously introduced problems are treated considering a large and complex distributed information system (i.e. intranet system) in a specific domain: medical folders and medical knowledge bases.