COGNITION AND INSTRUCTION, 1991, 8(4), 291-292 Copyright @ 1991, Lawrence Erlbaum Associates, Inc. Editor's Comment The following article and accompanying commentaries discuss an issue that is central to the Cognition and Instruction community: Through what mixture of laboratory and in situ applied research can cognitive principles best be made use- ful in instructional design? The lead article by Chandler and Sweller reports a series of experiments in which cognitive load theory, tested previously by Sweller and his colleagues in laboratory studies, is applied to the design of instruction in an industrial training setting. In a series of studies, instructional presentations consonant with the principles of the theory are shown to be more effective than traditional presentations of the same material. The studies are not claimed to test cognitive load theory but to validate its usefulness to instruction because of its capacity to generate effective new instructional techniques. Two commentators on the Chandler and Sweller article raise questions about the strategy of separating theory-testing research from applications research. Gold- man suggests that cognitive load theory is less prescriptive and constraining than the authors suggest and that, even with the theory as a guide, it is necessary to make many specific instructional design choices intuitively. Further, she argues, other theories suggest similar designs, and the studies reported cannot discriminate among the different theoretical accounts. She also argues that cognitive load the- ory cannot explain some differences in results on Chandler and Sweller's experi- ments. Accepting the power of their immediate practical results,...