Such scales include multiple items each of which aims to provide information about the construct under study (McNeish, 2018). In psychological research, subjective measurements are often used to assess constructs that are not directly observable. Results are discussed in relation to current trends in cognitive load theory and recommendations for the future use of cognitive load questionnaires in experimental research are suggested.

In particular, results seem to support the three-factor model consisting of intrinsic cognitive load, extraneous cognitive load, and germane cognitive load. Correlations among the cognitive load types partially contradict theory-based assumptions, whereas correlations with learning-related variables support assumptions derived from cognitive load theory. Moreover, moderator analyses showed that reliability estimates of the cognitive load questionnaires did not differ between educational settings, domains of the instructional materials, presentation modes, or number of scale points. Results revealed that the internal consistency of the subjective cognitive load questionnaires can be considered satisfactory across all four questionnaires. In this meta-analysis, four frequently used cognitive load questionnaires were examined concerning their reliability (internal consistency) and validity (construct validity and criterion validity). The increasing attention paid to cognitive load theory in educational science quickly culminated in the need to measure its types of cognitive load - intrinsic, extraneous, and germane cognitive load which additively contribute to the overall load. Based on this instructional theory, design recommendations and principles have been derived to manage the load on working memory while learning. For more than three decades, cognitive load theory has been addressing learning from a cognitive perspective.

Reliability in research