Cognitive Development 23 (2008) 435–451 Contents lists available at ScienceDirect Cognitive Development Beyond control of variables: What needs to develop to achieve skilled scientific thinking? Deanna Kuhn ∗ , Kalypso Iordanou, Maria Pease, Clarice Wirkala Columbia University, Teachers College, Department of Human Development, New York, NY 10027, United States article info Keywords: Scientific thinking Causal reasoning Multivariable prediction Epistemological understanding Argumentation abstract We identify three aspects of scientific thinking beyond the control- of-variables strategy that we claim are essential for students to master as a foundation for skilled scientific thinking. The first is strategic and involves the ability to coordinate effects of multiple causal influences on an outcome. The second is a mature under- standing of the epistemological foundations of science, recognizing scientific knowledge as constructed by humans rather than sim- ply discovered in the world. The third is the ability to engage in skilled argumentation in the scientific domain, with an apprecia- tion of argumentation as entailing the coordination of theory and evidence. We present new empirical data with respect to the first two of these competencies, supporting the claim that they are not well developed by early adolescence and warrant attention and provision of effective kinds of scaffolding. © 2008 Elsevier Inc. All rights reserved. Science educators who write about the development of scientific thinking skills emphasize the extent and complexity of what needs to develop if students are to become effective science learners (Duschl, 2008; Fortus et al., 2006; Kuhn & Pease, 2008)—a complexity and extent clearly reflected in K-12 science curriculum standards (National Research Council, 1996, 2007). A long-standing tradi- tion among developmental psychologists who study scientific reasoning, however, has been to focus attention on a single reasoning strategy, the control-of-variables strategy, featured by Inhelder and Piaget (1958) in their now classic volume (for early reviews, see Neimark, 1975, or Keating, 1980; for contemporary ones Zimmerman, 2007, or Kuhn, 2002.). Despite this volume of research, controversy continues regarding how this strategy develops and how educators can best support its development, and continuing investigation is warranted. In the present article, however, we turn our attention to ∗ Corresponding author. E-mail address: dk100@columbia.edu (D. Kuhn). 0885-2014/$ – see front matter © 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.cogdev.2008.09.006