Gerrits, LasseLasseGerritsVerweij, StefanStefanVerweij2019-09-192015-10-2920151356-3890https://fis.uni-bamberg.de/handle/uniba/39773Arguably, the current interest in the complexity sciences has its roots in the natural sciences, often in interplay with, and enhanced by, developments in mathematics and informatics. An oft-cited reason for this interest has been the increased ability of current computing systems to deal with complex mathematics and algorithms. As complexity gains more traction in the natural sciences, so it does in the social sciences (see e.g. Castellani, 2009). Naturally, complexity has also invaded the evaluation literature since the 1990s, where it is increasingly discussed and applied (cf. Walton, 2014). For instance, the journal Evaluation has recently published a steady number of complexity-related pieces. A search within the journal on the terms ‘complexity theory’, ‘complex system’ or ‘complexity science’ yielded forty-nine articles as part of an increasing trend. Inquiries with Scopus into complexity and evaluation yielded similar results. In this article, we take stock of recent progress and discuss what complexity holds for evaluation by discussing three recent books.engComplexityComplexity ScienceComplex SystemsEvaluationSystems Theoryarticlehttp://evi.sagepub.com/content/21/4/481