 A scientific theory is an explanation of a set of related observations, phenomena, or events based upon one or more hypotheses and verified multiple times by the evidence of detached groups of researchers. Cognitive load theory (CLT) was designed “to provide guidelines intended to assist in the presentation of information in a manner that encourages learner activities that optimize intellectual performance (Sweller et al. 1998 p. 25).” The theory proved successful in inspiring many experimental studies aimed at testing the CL effects of instructional design for over 20 years (Clark et al. 2006). On the other hand, a growing number of educational psychologists and researchers has identified many conceptual, methodological, and practical limitations of the theory (Bannert 2002; Brünken et al. 2009; Horz and Schnotz 2009; Moreno 2006; Schnotz and Kürschner 2007). The concerns voiced by de Jong (this issue) resonate with those critiques and suggest the need to reflect carefully on the scientific value of the theory.