In case-based reasoning, the adaptation of a source case in order to solve
the target problem is at the same time crucial and difficult to implement. The
reason for this difficulty is that, in general, adaptation strongly depends on
domain-dependent knowledge. This fact motivates research on adaptation
knowledge acquisition (AKA). This paper presents an approach to AKA based on
the principles and techniques of knowledge discovery from databases and
data-mining. It is implemented in CABAMAKA, a system that explores the
variations within the case base to elicit adaptation knowledge. This system has
been successfully tested in an application of case-based reasoning to decision
support in the domain of breast cancer treatment