**4. Cognitive load theory: a theoretical overview**

*Human cognitive architecture*, compromising of both working and long-term memory, is central to the importance of *cognitive load theory* [5]. The working memory is severely limited in its capacity to process unfamiliar information [39]; however, this limitation disappears when familiar information is retrieved from the long-term memory for processing. By contrast, long-term memory has an unlimited capacity, which enables it to store a large amount of information for an infinite period. Cognitive load theory, proposed by Sweller [5, 40], is an instructional theory that attempts to explain why a specific instruction will or will not work.

Three types of cognitive load affect the design of a specific instruction:


**iii.** *Germane cognitive load*, which entails an investment of cognitive resources to assist in the learning of relevant aspects of the instructional material. We can change the design of an instruction in order to increase germane cognitive load. For example, one way to improve problem-solving skills is to provide learners with variability practice, involving the identification of a category of problems that share a similar problem structure but have different contexts [42].

Recent research development on cognitive load theory has highlighted an important concept, known as *element interactivity*, that exists across the three types of cognitive load [43]. Element interactivity, in this case, emphasizes the *interaction that exists between elements within a learning material*. An element refers to anything that requires learning (e.g., a number, a symbol, a concept, a procedure, etc.) [44]. Under this conceptualization of cognitive load theory, the level of element interactivity determines the extent to which a particular type of cognitive load would exert its influence on the design of an instruction. Why is this the case? There are three possible reasons as to why this is the case: (i) the level of element interactivity determines the intrinsic nature of the material and, thus, the intrinsic cognitive load, (ii) the level of element interactivity determines, in part, the appropriateness and/or inappropriateness of an instruction and its extraneous cognitive load, and (iii) the level of element interactivity determines the beneficial design feature of an instruction and, thus, its corresponding germane cognitive load. Because cognitive resources, in the case of germane cognitive load, facilitate in the learning of relevant aspects of instructional material, germane cognitive load is not an independent source of cognitive load; rather, it is incorporated in the intrinsic cognitive load.
