This paper proposes a notion of indicative concepts in a transaction database, presents a
branch-and-bound optimization algorithm to find a top-N indicative concepts in a space of
many local minimum solutions. An indicative concept consists of several general items as
primitive events, but has a very small degree of correlation in spite of the generality of
component items. We regard those indicative concepts as rare patterns. As there exist trivial
patterns of general items with no instances, we introduce an objective function for taking into�…

A notion of rare patterns has been recently paid attention in several research fields including
Chance Discovery, Formal Concept Analysis and Data Mining. In this paper, we overview
the progress of our investigations on rare patterns satisfying a weak-correlation constraint. A
rare pattern must indicate some significance as well as a fact that the number of its instances
is a few. We pay our attention to a pattern as an itemset in a transaction database which
consists of several general items, but has a very small degree of correlation in spite of the�…