This article, authored by Glenda Eoyang and Thomas Berkas for the Human Systems Dynamics Institute, describes key features of a complex adaptive system and what these might mean for evaluation and the role of an evaluator.
"Evaluation is a central issue in all organizations. Many standard evaluation tools, techniques and methods rely on basic assumptions about linear organizational dynamics (predictability, low dimensionality, system closure, stability and equilibration). Some of these assumptions are not valid when a system enters the regime of a complex adaptive system (CAS). New strategies are required to evaluate complex adaptive human systems. New tools, techniques and methods must integrate assumptions about the dynamical and complex nature of human systems. This chapter summarizes the characteristics of CASs from an organizational perspective. It identifies properties of an evaluation system that are consistent with the nature of a CAS and describes tools and techniques that promise more effective evaluation. Finally, it outlines the emergent role of the evaluator in a complex environment." (Eoyang & Berkas 1999)