The Effects of Split-Attention and Redundancy on Cognitive Load When Learning Cognitive and Psychomotor Tasks

Human working memory can be defined as a component system responsible for the temporary storage and manipulation of information related to higher level cognitive behaviors, such as understanding and reasoning (Baddeley, 1992; Becker & Morris, 1999). Working memory, while able to manage a complex array of cognitive activities, presents with an unexpected peculiarity, in that only a few elements of information can be processed in working memory at a given time. Miller (1956) established that working memory can only maintain about seven elements of information at a time. Additionally, working memory under conditions where rehearsal is limited, may only be able to hold information active for a few seconds (Peterson & Peterson, 1959). In situations involving more complex cognitive tasks, demands placed on working memory that are not directly related to problem solving can hinder learning by exceeding available cognitive resources (Sweller, van Merrienboer, & Paas, 1998). In such situations, instructional principles that avoid overburdening working memory and/or direct the learner's available resources are needed to design efficient and effective instruction. Cognitive load theory, as conceptualized by Sweller (1988) and his colleagues in the late eighties, is concerned with instructional design and message design methods that efficiently manage the limited processing capabilities of an individuals working memory while capitalizing on the extensive capabilities of long term memory in order to promote schema formation and improve intellectual learning and performance of complex cognitive tasks. Cognitive load (CL) is defined as the " total amount of mental energy imposed on working memory at an instance in time " (Cooper, 1998, p. 10). This " total " cognitive load is further subdivided into three subcomponents: intrinsic cognitive load (ICL), extraneous cognitive load (ECL) and germane cognitive load (GCL) (Sweller et al., 1998). Intrinsic cognitive load is the load imposed on the learner by the nature of the instructional material that must be proces sed and learned. There is evidence to support the indirect manipulation of ICL by incorporating sequencing and layering strategies into the instructional design process and learning task (Pollock, Chandler, & Sweller, 2002). Extraneous cognitive load is the load imposed by factors such as instructional strategies, message design, interface design, and the quality of instructional materials and learning environments. ECL is readily influenced by instructional design processes and has been the focus of mu ch investigation (Sweller et al., 1998). In simple terms, high ECL equates to a reduction in working …