Cognitive Load: recommendations for the classroom
Cognitive load theory has produced a number of recommendations regarding instructional techniques that are directly transferable to the classroom. A selection of these are described in the Cognitive Load Theory report from the Centre for Education, Statistics and Evaluation, Education New South Wales, 2017). They illustrate how evidence-based cognitive load research can be used by teachers to improve student outcomes.
The ‘worked example effect’
A ‘worked example’ is a problem that has already been solved for the learner, with every step fully explained and clearly shown. The ‘worked example effect’ is the widely replicated finding that novice learners who are given worked examples to study perform better on subsequent tests than learners who are required to solve the equivalent problems themselves.
The reason for this, according to cognitive load theory, is that unguided problem-solving places a heavy burden on working memory, inhibiting the ability of the learner to transfer the information into their long-term memory. The learner may effectively solve the problem, but because their working memory was overloaded they may not recognise and remember the rule that would allow them to quickly solve the same problem again in the future.
The ‘expertise reversal effect’
The ‘expertise reversal effect’ is an important exception to the worked example effect. According to the expertise reversal effect, the heavy use of worked examples becomes less and less effective as learners’ expertise increases, eventually becoming redundant or even counter-productive to learning outcomes.
This means that some instructional procedures such as worked examples, which assist learning for novices because they reduce cognitive load, are not effective for teaching more expert learners. While cognitive load theory supports fully guided instruction for novice learners, it also supports the gradual incorporation of more independent problem-solving tasks as learners gain expertise.
The ‘redundancy effect’
Students do not learn effectively when their limited working memory is directed to unnecessary or redundant information. The ‘redundancy effect’ occurs when learners are presented with additional information that is not directly relevant to learning, or with the same information in multiple forms. An example is a textbook which includes both text and a diagram that needlessly repeat information, or a PowerPoint presentation in which the presenter reads the text presented on the screen. Requiring learners to process redundant information inhibits learning because it overloads working memory.
Cognitive load research shows that best practice is to remove redundant information from learning material. Sweller argues: ‘Most people assume that providing learners with additional information is at worst, harmless and might be beneficial. Redundancy is anything but harmless. Providing unnecessary information can be a major reason for instructional failure.’
The ‘split attention effect’
The ‘split attention effect’ occurs when learners are required to process two or more sources of information simultaneously in order to understand the material. This might occur, for example, when a diagram is used to explain a concept, but it cannot be understood without referring to a separate piece of explanatory text. In this instance the learner is required to hold both sources of information in their working memory at the same time and to mentally integrate the two. This places a high cognitive load on the working memory, interfering with the ability of the learner to transfer the relevant information to their long-term memory.
The split-attention effect can be minimised or eliminated by physically integrating separate sources of information so that they do not have to be mentally integrated by the learner. Sweller, van Merrienboer & Paas argue: ‘Split attention occurs very commonly in instructional contexts. On the basis of dozens of experiments under a wide variety of conditions, the evidence suggests overwhelmingly that it has negative consequences and should be eliminated wherever possible.’
The ‘modality effect’
The 'modality effect' is associated with the split attention effect, but offers an alternative technique to reduce cognitive load than physically integrating separate sources of information. Instead, it is also possible to decrease extraneous load on working memory by using more than one mode of communication – both visual and auditory. Evidence suggests that working memory can be subdivided into auditory and visual streams (Baddeley 1983, 2002; Baddeley & Hitch 1974), so presenting information using both auditory and visual working memory can increase working memory capacity. For example, when using a diagram and text to explain a concept, the written text can be communicated in spoken form. Using both auditory and visual channels increases the capacity of working memory, and facilitates more effective learning.