Cognitive load

The cognitive load theory was developed in 1998 by John Sweller, and the School of Education at New South Wales University released a paper in August 2017 that carefully examined the theory (Heick, 2017:1). The paper explains that: “Cognitive load theory is based on the fact that the human brain processes and stores information. The human memory can be divided into working memory and long-term memory. Information is stored in the long-term memory in the form of schemas and that processing new information results in ‘cognitive load’ on working memory which can affect learning outcomes,” (ibid).

In other words, the Cognitive load theory maintains that, because short-term memory is limited, learning experiences should be designed to reduce working memory ‘load’ in order to promote schema acquisition (Heick, 2017:1). Use of short-term memory and use of working memory cannot be done at the same time. For instance, supposing a teacher asks learners to critically examine various named systems, which require higher-order thinking, while also defining and ‘making sense of’ what the ‘named system’ is and how it works, the teacher would be overloading the learners’ short-term memory. This is so because the learners do not yet ‘understand’ the named systems. It means the learners would need to consistently access their short-term memory while processing – while ‘learning.’ The concept of ‘the named systems’ is not yet in their long-term memory. So, as they ‘create knowledge,’ that is, moving new information into existing or emerging schema, their short-term memory becomes overwhelmed because it is the primary ‘ground zero’ for the learning. For the learners to learn under such circumstances, they would be fighting an up-hill battle. That explains the cognitive load theory (Heick, 2017:1).

69 Definition of Cognitive load theory

Sweller, (1988:257) defined his cognitive load theory as a theory that offers guidance that is meant to help in the presentation of information in a way that enhances pupil activities that increase academic achiement. This theory asserts that working memory has a limited capacity that includes partly self-determining factors to deal with auditory/verbal material and visual/2- or 3-dimentional information as well as an efficiently long-term memory that is not limited, keeping schemas that vary in their degree of mechanisation. For instructional activities are enhanced when the working memory load is reduced and schema construction is encouraged. According to Sweller (2011:37-76), cognitive load theory employs evolutionary theory to make human cognitive architecture and use it to develop new instructional actions. The theory asserts that information can be separated into biologically primary knowledge that we have evolved to acquire and biologically secondary knowledge that is important for cultural activities. Secondary knowledge, unlike primary knowledge, is the subject of instruction. It is processed in a way that is comparable to the manner in which biological evolution processes information. When dealing with secondary knowledge, human mental processes require a very large information store, the contents of which are required largely by obtaining information from other information stores.

Baddeley (1992:281) defines working memory as the system for short-term maintenance and processing of information, that is needed for the performance of complex cognitive activities such as comprehension, learning and reasoning.

Depending on the prevailing circumstances, pupils can find learning varying between being very easy to being very hard (Sweller, 1994:295). In one instance, some pupils were asked to describe their experience with the dentist when the majority of them had never been to a dentist. When lack of the necessary background knowledge that is needed to do an assignment or to learn new information is added to language difficulties, learners experience a heavy ‘cognitive load.’ which is usually lightened if the learners are at least able to draw on their own experiences and knowledge. For instance, during ES lessons, the teacher and pupils should be encouraged to include traditional dishes when they give examples of proteins, carbohydrates, foods rich in starch, fats, etc. Other examples might comprise the following: traditional medicines and herbs, flora and fauna from the learners’ environment, shelter and habitats,

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agricultural products and food preservation methods, reproduction and contraception, issues of conservation (e.g. through taboos and totems), beliefs, norms and values. Inappropriate instructional designs can impose a heavy extraneous cognitive load that inhibits learning. Learning becomes very difficult if cognitive load is high (Sweller, 1994:308).

The Cognitive Load Theory (CLT) is a theory that explains how the cognitive load produced by learning tasks can inhibit learners’ ability to process new information and to create long-term memories. There are three types of cognitive load, namely: intrinsic cognitive load, extraneous cognitive load and germane cognitive load (Heick, 2017:01). Intrinsic cognitive load is difficult to eliminate because there will always be difficult concepts to teach in science. However, the teacher can reduce it by breaking it down into smaller, simpler steps that are easier for pupils to tackle.

Extraneous cognitive load is created by difficulties imposed on the learners by the teacher. Pupils can have difficulties in following the teacher’s instructions. They should be simple, clear and straight forward for all pupils to follow. Lack of proficiency in the LoLT can also contribute to the creation of an extraneous cognitive load. Instructions in ESL should be explained to make sure all pupils are aware of the tasks to be done. If there is need, the teachers can also code-switch to the pupils’ indigenous language to make sure that all the pupils have understood what is expected of them. Use of ineffective teaching methods can also cause pupils to face challenges. Some concepts are better explained when illustrated with a diagram as opposed to a verbal narration only. Other concepts are easier to comprehend when demonstrated visually using models or video illustrations, e.g. eclipse of the sun or moon. Germane cognitive load is produced by the building of schemas. Schemas are what permit us to treat multiple elements as a single element. They are the cognitive structures that make up the knowledge base (Sweller, 1988:260). Schemas are acquired over a life time of learning, and may have other schemas within themselves. The difference between an expert and a novice is that a novice has not acquired the schemas of an expert. Learning requires a change in the schematic structures of long-term memory and is confirmed by performance that progresses from awkward, error-prone, sluggish and hard to smooth and effortless. This change occurs because as the novice becomes increasingly familiar with the material, the cognitive characteristics associated with the material are altered so that it can be handled more efficiently by working memory. From an instructional perspective, information in instructional material must first be processed by working memory. For schema acquisition to occur, lesson delivery should be designed to lessen the working memory load. Cognitive load theory is concerned

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with techniques for reducing working memory load in order to ease the changes in long-term memory associated with schema acquisition (Sweller, 1988:261).

Germane load is advantageous because it assists in learning new skills and other information. A memory schema is a conceptualisation of a particular idea or object that tells us what to expect when we encounter it in future. We hold schemas for people, objects, events, roles, etc. The first time we experience something new can be frightening, as we do not have a schema that tells us what to expect, thereby producing a germane cognitive load. An example is boarding an aeroplane for the first time. The first experience helps us to anticipate and understand it in future.

Application of the cognitive load theory (CLT)

CLT has many implications in the design and production of learning materials which must, if they are to be effective, keep the cognitive load of the learners at a minimum during the learning process (Sweller, 1999:1). Teachers can apply the CLT to help pupils learn ES more effectively. By simplifying concepts, providing individual, easy to understand explanations and removing superfluous details, they can reduce extraneous cognitive load to make their ES lessons very effective and enjoyable.