Cognitive Load Theory (hereafter CLT) is a cognitive psychology theory about the mental effort placed on working memory during learning. CLT divides cognitive load into three kinds: intrinsic load, extraneous load, and germane load. The key point is that working memory, which has to bear this load, is extremely limited.
I also extend CLT beyond learning to knowledge work in general. Because human working memory is so limited, it is better to minimize the workload in knowledge work.
In algorithmic terms, it is like solving algorithm problems on a computer with very little RAM. So you should design your workflow to reduce space complexity rather than time complexity.
Types of Cognitive Load
CLT divides cognitive load into the following three types. Here, writing serves as the example.
Intrinsic Load
This is the load inherent in the cognitive task itself, which cannot be reduced.
In the writing example, it looks like this:
- Coming up with ideas
- The complexity that comes from the topic itself
- Composing sentences
I said it cannot be reduced, but in the long run it can be. If the topic is familiar, intrinsic load decreases. Still, it is hard to reduce intrinsic load immediately. Think of intrinsic load as a solid core that you can neither increase nor decrease.
Extraneous Load
This is the load unrelated to the cognitive task itself. This load can increase or decrease, and the less of it, the better. For example, you could say that all UX aims to reduce this extraneous load.
In the writing example, it looks like this:
- The fatigue of editing because my handwriting is terrible
- Phone notifications while writing
- The load that comes from keeping the overall flow in my head instead of writing it down somewhere
Germane Load
This is the load spent on building and automating schemas. If you take on this load, you get better at writing itself, and you come to understand your subject more fully.
In the writing example, it looks like this:
- Turning vague thoughts into sentences
- Summarizing complex content simply
The heart of CLT seems to lie precisely in this germane load.
Good Load, Bad Load
In strength training, you increase the load on the target muscle and treat unrelated stimulus as compensation, reducing its load. In knowledge work too, designing with a clear awareness of which area you are stimulating should help you improve.
By the definition of cognitive load, the ones you can adjust are extraneous load and germane load.
The positive direction is to lower extraneous load and raise germane load. The negative direction is the opposite.
Here is a problem with lowering germane load: