This paper describes an intelligent data retrieval system, designed fo
r the Epidemiological Observatory of Emilia Romagna, named IDEA. This
system is an attempt to formalize the interaction between the data log
ical view and its real physical organization in databases. The formali
zation chosen comes from expert-system knowledge representation techno
logy, following an approach similar to McClay. Its implementation has
been realized using an object-oriented library of SICStus Prolog and t
he APPEAL programming environment. The resulting system can be seen as
the basic component of a general-purpose decision support system, who
se development is foreseen in the near future.