What is CLT

Cognitive load theory aims to explain how the information processing load induced by learning tasks can affect students’ ability to process new information and to construct knowledge in long-term memory. Its basic premise is that human cognitive processing is heavily constrained by our limited working memory which can only process a limited number of information elements at a time. Cognitive load is increased when unnecessary demands are imposed on the cognitive system. If cognitive load becomes too high, it hampers learning and transfer. Such demands include inadequate instructional methods to educate students about a subject as well as unnecessary distractions of the environment. Cognitive load may also be increased by processes that are germane to learning, such as instructional methods that emphasise subject information that is intrinsically complex. In order to promote learning and transfer, cognitive load is best managed in such a way that cognitive processing irrelevant to learning is minimised and cognitive processing germane to learning is optimised, always within the limits of available cognitive capacity.

Cognitive load theory is primarily concerned with the acquisition of biologically secondary knowledge—knowledge that is culturally important and must be explicitly taught, such as reading, writing, mathematics, and scientific reasoning. This type of information is the focus of formal education and is not acquired naturally without instructional support. However, cognitive load theory does not ignore biologically primary knowledge. On the contrary, it recognises that instructional techniques can harness biologically primary knowledge—such as our evolved capacities for gesture, imitation, spoken language, and visual perception—to support the acquisition of biologically secondary knowledge. For example, tracing or gesturing during mathematics instruction leverages our natural motor and perceptual systems to reduce cognitive load and enhance learning. In this way, cognitive load theory integrates insights about biologically primary knowledge to design more effective instruction for biologically secondary learning goals.

The cognitive architecture required to process biologically secondary information consists of biologically primary processes that provide a base for cognitive load theory. These principles provide the cognitive architecture that underlies the instructional procedures of cognitive load theory.

1. The Information Store Principle: Human cognition requires a large store of information, i.e. long-term memory.

2. The Borrowing and Reorganising Principle: The vast bulk of information stored in long-term memory comes from other people. Humans are intensely social with powerfully evolved procedures for obtaining information from others.

3. The Randomness as Genesis Principle: If no one is available from whom to borrow the information, it will need to be generated, using a random generate and test procedure during problem solving. 

4. The Narrow Limits of Change Principle: Working memory is severely limited when processing novel information. 

5. The Environmental Organising and Linking Principle: There are no known limits when familiar, organized information from long-term memory is processed. 

Based on cognitive load theory, several thousand randomly controlled trials have been published since the late 1980’s. Replications with different students (from primary schools to professional training), on different topics (e.g. STEM, second language learning, medical education), in different countries, identified certain ‘effects’ for instructional design. Several of these effects has been reviewed in meta-analyses.

1. Goal-free effect: Replace conventional tasks with goal-free tasks that provide learners with a non-specific goal.

2. Worked example effect: Replace conventional tasks with worked examples that provide learners with a solution they must carefully study.

3. Completion problem effect: Replace conventional tasks with completion tasks that provide learners with a partial solution they must complete.

4. Split-attention effect: Replace multiple sources of information, distributed either in space (spatial split attention) or time (temporal split attention), with one integrated source of information.

5. Redundancy effect: Replace multiple sources of information that are self-contained (i.e. they can be understood on their own) with one source of information.

6. Element interactivity effect: Cognitive load effects that are found for high element interactivity materials are typically not found for low element interactivity materials. Actually, cognitive load theory is only relevant for complex learning.

7. Variability effect: Replace a series of tasks with similar surface features with a series of tasks that differ from one another on all dimensions on which tasks differ in the real world.

8. Modality effect: Replace a written explanatory text and another source of visual information (unimodal) with a spoken explanatory text and the visual source of information (multimodal).

9. Self-explanation effect: Replace separate worked examples or completion tasks with enriched ones containing prompts, asking learners to self-explain the given information.

10. Imagination effect: Replace conventional study of a procedure or concept to learn with imagination, where the learner is asked to imagine or mentally practice the concept or procedure.

11. Isolated elements effect: Replace a presentation of information/tasks with all interacting elements at once by initially presenting elements of information sequentially in an isolated form rather than in a fully interactive form.

12. Expertise reversal effect: Cognitive load effects that are found for low expertise learners (e.g. worked example effect, goal free effect) are typically not found or even reversed for high expertise learners.

13. Guidance-fading effect: Cognitive load effects that are relevant in the beginning of a longer educational program (e.g. guided problem-solving, worked examples) are no longer relevant in later stages of the program, after the learners acquired sufficient expertise.

14. Collective working memory effect: Replace individual learning tasks with collaborative tasks so that more cognitive resources become available.

15. Transient information effect: Cognitive load effects that are found for transient information (e.g. self-pacing effect, segmentation effect, modality effect) are typically not found for non-transient or less transient information.

16. Human movement effect: Replace static or unrealistic visualisations with visualisations showing human movements.

17. Self-management effect: Cognitive load effects that are found for ill-designed instructional materials (e.g. split attention) are not found when learners are explicitly taught how to reduce the associated extraneous load.

18. Working memory resource depletion effect: Replace prolonged periods of cognitively demanding tasks involving similar cognitive processes with shorter tasks separated by rest intervals to restore depleted working memory resources.