Abstract
The practically usable measures of cognitive load are important for evaluating learning and performance conditions, and obtaining empirical evidence in support of theoretical hypotheses. Subjective rating scales remain popular tools for measuring cognitive load, especially in realistic environments, despite the development of more technically sophisticated objective measures that are suitable mostly for laboratory settings only. In accordance with the traditional view of cognitive load theory, a number of studies suggested subjective rating scales aimed to differentiate three types of cognitive load -- intrinsic, extraneous, and germane. However, according to a recently proposed modified theoretical model of cognitive load, germane load shares the identical theoretical ground with intrinsic load and therefore, is redundant. It has been hypothesized that rating scales based on the two-factor, intrinsic-extraneous model of cognitive load should be sufficient and valid tools for assessing levels of cognitive load. The reported study tested this hypothesis by conducting a confirmatory factor analysis of multidimensional rating data using the lavaan package in the programming language R. The results of the analysis supported the two-factor model of cognitive load.