Understanding instructional design effects by differentiated measurement of intrinsic, extraneous, and germane cognitive load

Instructional design deals with the optimization of learning processes. To achieve this, three aspects need to be considered: (1) the learning task itself, (2) the design of the learning material, and (3) the activation of the learner's cognitive processes during learning. Based on Cognitive Load Theory, learners also need to deal with the task itself, the design of the material, and the decision on how much to invest into learning. To link these concepts, and to help instructional designers and teachers, cognitive load during learning needs to be differentially measured. This article reviews studies using a questionnaire to measure intrinsic, extraneous and germane cognitive load in order to provide evidence for the instruments' prognostic validity. Six exemplary studies from different domains with different variations of the learning material were chosen to show that the theoretically expected effects on different types of load are actually reflected in the learners' answers in the questionnaire. Major hypotheses regarding the different load types were (1) variations in difficulty are reflected in the scale on intrinsic cognitive load, (2) variations in design are reflected in the scale on extraneous cognitive load, and (3) variations in enhancing deeper learning through activation of cognitive processes are reflected in the scale on germane cognitive load. We found prognostic validity to be good. The review concludes by discussing the practical and theoretical implications, as well as pointing out the limitations and needs for further research.