Cognitive Architecture and Instructional Design: 20 Years Later

There have been major developments in cognitive load theory over the last 20 years. First, its theoretical basis has been strengthened by laying a strong foundation for human cognitive architecture in evolutionary psychology. Second, four-component instructional design (4C/ID) has been developed as a twin theory focussing on the design of educational programs of longer duration (courses or whole curricula). Third, research yielded a series of new cognitive load effects, including the so-called compound effects, that is, effects that alter the characteristics of other, simple cognitive load effects. Fourth and finally, new instruments have been developed to measure different types of cognitive load. We will begin by considering theoretical developments based on evolutionary psychology.

Human Cognitive Architecture Seen Through the Prism of Evolutionary Psychology

While our 1998 version of human cognitive architecture, with its emphasis on the intricate relations between working memory and long-term memory, provided a critical aspect of how we learn, think and solve problems, the continual advances in our knowledge of human cognition indicated a need to expand that earlier conceptualisation. Much of that expansion revolved around evolutionary psychology which provided an impetus for that work.

Based on Geary’s distinction between biologically primary and secondary knowledge (Geary 2008, 2012; Geary and Berch 2016), evolutionary educational psychology allows us to categorise information in instructionally meaningful ways that now are central to cognitive load theory (Sweller 2016a). Biologically primary knowledge is knowledge that we have evolved to acquire over countless generations. That category of knowledge tends to be critically important to humans providing, as examples, knowledge that allows us to listen and speak, recognise faces, engage in basic social functions, solve unfamiliar problems, transfer previously acquired knowledge to novel situations, make plans for future events that may or may not happen, or regulate our thought processes to correspond to our current environment. Humans must learn to engage in these very complex cognitive activities but because of their importance, we have evolved to acquire the necessary skills effortlessly and automatically. Consequently, they cannot be taught to most people.

Biologically primary knowledge is modular with little relation between the cognitive processes associated with one skill and another (Geary 2008, 2012). Each skill is likely to have evolved in different evolutionary epochs requiring very different cognitive processes. Our ability to regulate our thought processes to correspond to our current environment is likely to have evolved before we became modern humans as did our tendency to use gestures to communicate, while our ability to organise our lips, tongue, breath and voice to speak is likely to have evolved far more recently.

A very large number of biologically primary skills are generic-cognitive in nature such as general problem-solving skills or even our ability to construct knowledge (Sweller 2015, 2016b; Tricot and Sweller 2014). A generic-cognitive skill is a basic cognitive skill that we have evolved to acquire instinctively because it is indispensable to a very wide range of cognitive functions. Generic-cognitive skills tend to be more concerned with how we learn, think and solve problems rather than the specific subject matter itself. Over the last few decades, many educationalists, correctly realising the importance of such skills, have advocated that they be taught. Such campaigns tend to fail, not because the skills are unimportant but because they are of such importance to humans that we have evolved to acquire them automatically without instruction. The enormous emphasis on teaching general problem-skills last century provides an example. Evidence for the effectiveness of teaching generic-cognitive skills requires randomised, controlled trials using far transfer tests. Far transfer is required because the rationale of generic-cognitive skills is that they will enhance performance over a wide range of areas and, of course, it is essential to ensure that any performance improvement is not due to domain-specific knowledge.

It should be noted that while the acquisition of biologically primary skills tends to occur automatically and unconsciously without explicit teaching, it does not follow that use of the skills occurs unconsciously in every context. For example, we learn to speak our native language unconsciously without explicit effort but may require considerable effort to find appropriate words with appropriate meanings in any given situation. We need to learn how to use biologically primary knowledge in specific domains, which leads to biologically secondary knowledge.

Biologically secondary knowledge is knowledge we need because our culture has determined that it is important. Examples of biologically secondary information can be found in almost all topics taught in education and training contexts. Educational institutions were invented because of our need for people to acquire knowledge of biologically secondary information.

We have evolved to acquire secondary knowledge but it is acquired very differently to primary knowledge. Except insofar as it is related to primary knowledge, secondary knowledge is not modular but rather, is part of a single, unified system. Because it is a unified system, there are considerable similarities in acquiring biologically secondary knowledge irrespective of the domain under consideration. All secondary knowledge tends to require conscious effort on the part of the learner and explicit instruction on the part of an instructor. It is rarely acquired automatically. The distinction between the two processes can be exemplified by the distinction between learning to listen and learning to read. As indicated above, we learn to listen automatically, without tuition. Most people do not learn to read automatically. Despite reading and writing having been invented thousands of years ago, few people learned to read and write until the advent of modern education very recently.

In contrast to the generic-cognitive skills associated with most biologically primary knowledge, biologically secondary knowledge is heavily domain-specific (Sweller 2015, 2016b; Tricot and Sweller 2014). We have evolved to learn how to solve a variety of problems using generic-cognitive skills. We have not specifically evolved to learn how to read and write a particular word in English or Chinese, or that the best first move when solving a problem such as (a + b)/c = d, solve for a, is to multiply both sides by the denominator on the left side. These domain-specific, biologically secondary skills need to be explicitly taught (Kirschner et al. 2006; Sweller et al. 2007) and actively learned.

Most educationists intuitively understand that generic-cognitive skills are far more important to human functioning than domain-specific skills and this understanding has led to a substantial emphasis on generic-cognitive skills. Nevertheless, there is an increasing recognition that while domain-specific skills are eminently teachable, purely generic-cognitive skills are not teachable and attempts to teach them lead to dead-ends (Sala and Gobet 2017). The previous emphasis on generic-cognitive skills is due to a failure to realise the distinction between biologically primary and secondary knowledge (Tricot and Sweller 2014). An accent on teaching generic-cognitive skills was, of course, present in 1998 with the popularity of teaching generic problem-solving skills. The 1998 paper was partially a reaction to that accent. That phase has passed but other generic-cognitive skills have replaced that emphasis with, as indicated by Sala and Gobet, no greater success. Furthermore, despite about a century of effort, there is little evidence from far transfer studies, that generic-cognitive skills which transcend domain-specific areas can be taught. The ‘natural’, minimal guidance procedures used to acquire biologically primary, generic-cognitive skills are inappropriate for the acquisition of biologically secondary, domain-specific skills that tend not to be acquired easily, unconsciously and automatically.

The data summarised by Sala and Gobet (2017) provide a major justification for the post 1998 inclusion of evolutionary psychology into cognitive load theory. Of course, none of the above eliminates the possibility of new data becoming available indicating the possibility of teaching purely generic-cognitive skills leading to far transfer effects. Should a substantial body of such data become available, further modifications to cognitive load theory would be required.

We should not conclude from the above argument that biologically primary knowledge and generic-cognitive skills are irrelevant to instructional issues. While we doubt that attempts to teach biologically primary, generic-cognitive skills will be successful, they can be used to assist in teaching biologically secondary, domain-specific skills (Paas and Sweller 2012). For example, students may know how to randomly generate problem solution moves without being instructed in the procedures to do so, but may not be aware of the domain-specific conditions where the technique might be effective. Pointing out to students that a generic-cognitive skill should be used on a particular class of specific problems can be instructionally effective (Youssef-Shalala et al. 2014). Furthermore, it is important to note that teaching anything involves a combination of primary and secondary skills with the secondary skill being the only part that is learned. For example, medical doctors are taught how to effectively communicate in an emergency team using the SBAR method, always reporting on the situation, background, assessment and recommendations (Beckett and Kipnis 2009). Obviously, the SBAR method can be taught because doctors are able to speak with each other. But, although it makes no sense to teach doctors how to speak with each other in a generic sense because this is primary knowledge, teaching them the specific SBAR method is secondary knowledge and might have a very positive effect on team communication in emergency situations.

The cognitive architecture required to process biologically secondary information consists of biologically primary processes that provide a base for cognitive load theory. Together, the processes mimic the information processing procedures of biological evolution (Sweller and Sweller 2006) and can be described as constituting a natural information processing system. They can be described by five basic, biologically primary principles. These principles provide the cognitive architecture that underlies the instructional procedures of cognitive load theory.