The Mirroring Hypothesis: Theory, Evidence and Exceptions

The mirroring hypothesis predicts that the organizational patterns of a development project (e.g. communication links, geographic collocation, team and firm co-membership) will correspond to the technical patterns of dependency in the system under development. Scholars in a range of disciplines have argued that mirroring is either necessary or a highly desirable feature of development projects, but evidence pertaining to the hypothesis is widely scattered across fields, research sites, and methodologies. In this paper, we formally define the mirroring hypothesis and review 102 empirical studies spanning three levels of organization: within a single firm, across firms, and in open community-based development projects. The hypothesis was supported in 69% of the cases. Support for the hypothesis was strongest in the within-firm sample, less strong in the across-firm sample, and relatively weak in the open collaborative sample. Based on a detailed analysis of the cases in which the mirroring hypothesis was not supported, we introduce the concept of actionable transparency as a means of achieving coordination without mirroring. We present examples from practice and describe the more complex organizational patterns that emerge when actionable transparency allows designers to "break the mirror."