In this paper, we study the problem of discovering interesting pattern
s in large volumes of data. Patterns can be expressed not only in term
s of the database schema but also in user-defined terms, such as relat
ional views and classification hierarchies. The user-defined terminolo
gy is stored in a data dictionary that maps it into the language of th
e database schema. We define a pattern as a deductive rule expressed i
n user-defined terms that has a degree of certainty associated with it
. We present methods of discovering interesting patterns based on abst
racts which are summaries of the data expressed in the language of the
user.