Educational innovations often involve intact subgroups, such as school classes or university departments. In small-scale educational evaluation research, typically involving 1 to 20 subgroups, differences among these subgroups are often neglected. This article presents a mixed method from a qualitative perspective, in which differences among intact subgroups regarding one construct or effect are first quantitatively identified and subsequently qualitatively described and explained by differences among the contexts of the separate intact subgroups. Its focus on the contexts of intact subgroups, where organizational factors can be modified, makes this method interesting from a management perspective. In evaluations, repeated application of the method deserves a place beside other analytical methods.