  Pattern discovery, the process of discovering previously unrecognized
patterns, is often performed as an ad-hoc process with little resulting
certainty in the quality of the proposed patterns. Pattern validation, the
process of validating the accuracy of proposed patterns, remains dominated by
the simple heuristic of "the rule of three". This article shows how to use
established scientific research methods for the purpose of pattern discovery
and validation. We present a specific approach, called the handbook method,
that uses the qualitative survey, action research, and case study research for
pattern discovery and evaluation, and we discuss the underlying principle of
using scientific methods in general. We evaluate the handbook method using
three exploratory studies and demonstrate its usefulness.

Artificial Intelligence;Databases;Machine Learning