Cognitive load and Cognitive Load Theory

This post was inspired by a blog on the ‘TeacherToolkit’. The original work is here: http://edrev.asu.edu/edrev/index.php/ER/article/viewFile/2025/545

What is meant by cognitive load?

Cognitive load refers to the total amount of mental effort being using by working memory, or, as it is more commonly known, short-term memory in the completion of a task.

Take this example which requires a great deal of working memory to solve: Andrew is forty years old. Carrie is four years older than Jane who is two years younger than Andrew. Jane is twice the age of Sue who is the same age as Bill who is one year younger than Pam. How old is Pam?

What is the impact of heavy cognitive load on students’ ability to learn?

Cognitive Load Theory states that when working memory is over worked or overloaded, the resulting learning will be of less importance than if working memory was not over worked or overloaded. Therefore, by reduced cognitive load, pupils will learn more from completing tasks and solving problems. For instance, in the question above, without the aid of a pen and paper (or indeed having the luxury of the problem written down in a permanent form), it necessitates too much working memory to take anything away from the task except its answer (Pam is twenty); any learning of potential rules or valuable problem solving lessons are lost.

So what can we do to reduce students’ cognitive load?

  • It has been argued that reducing cognitive load by simplifying technical language and removing specialist knowledge is actually harmful to students. The Expertise Reversal Effect occurs when knowledge that is needed and has been acquired is lost and pupils become deskilled. To avoid this, we need to transfer key knowledge into students’ long-term memory so that remembering what a simile is or that Henry VIII was the second Tudor Monarch places no burden on working memory.
  • Studies have shown that while individuals have very limited working memory, by collaborating, in effect they are pooling their working memories. Provided that the costs of collaborating are less than the increase in working memory due to pooling, performance should be increasing compared to individual learning.
  •  Providing unnecessary information can be a major reason for instructional failure. In the worked example about age, we do not need to know that “Carrie is four years older than Jane” or that “Sue…is the same age as Bill” to get the correct answer. Adding in this material places further demands on an already heavy cognitive load. Such additional information can come in the form of information, redundant or non-sequential instruction or images that do not relate in very specific ways to the material.
  • Element interactivity also contributes to the negative effects of cognitive load. If elements of information must interact with one another (as in the example), they must be processed simultaneously in working memory to be properly understood, imposing a heavy cognitive load. Physically integrating various sources of information, for instance, in written or image form, so that they no longer have to be mentally integrated will reduce extraneous cognitive load and facilitate learning.
  • Finally, research conducted in the field of cognitive load suggests that adopting a “goal free” approach to teaching and learning may be of some value. When students must get from one item to another e.g. get from 108 to 8 in two mathematical moves, rather than looking for a rule or lesson, they will look for the easiest way to get there. Instead, a mixture of looking at worked examples, studying completed tasks with missing steps in them or working backwards from an answer may be more useful in attempting to facilitate learning.