Cognitive Load
Cognitive load is the amount of mental resources needed to understand and interact with an interface.
The concept of cognitive load is tightly connected to working memory. You can think of working memory as the capacity for information we can handle while doing a task. The key thing is that the working memory is limited.
Types of cognitive load
There are three types of cognitive load.
Intrinsic
Intrinsic cognitive load is how hard something is to learn. Think of it as the natural difficulty of learning something. Some things are just harder to learn because they have more parts to understand at the same time.
Compare these examples.
- Solving "2 + 2 = ?" is easy.
- Solving math problems like this is harder: "A store sells apples for $2 each. If you buy 3 apples and pay with a $10 bill, how much change do you get?"
Extraneous
Extraneous cognitive load is the extra mental effort you have to use because of bad instructions, a confusing design, or unnecessary distractions. It makes learning harder than it needs to be.
Compare these examples.
- 2 + 2 = ?
- Consider the sum of two numerical values, each equivalent to the integer 2, and determine the result.
The second example has high extraneous cognitive load. It's way simpler to understand the first one.
Germane
Germane cognitive load is the mental effort your brain uses to make learning stick. It's the part of learning that helps you truly understand, process, and remember new information.
If we compare these three types, it would look like:
- Intrinsic load = The built-in difficulty of what you're learning.
- Extraneous load = The extra confusion that makes learning harder.
- Germane load = The effort your brain uses to actually learn and understand.
Our goal is to reduce extraneous load and focus on germane load. It means that we should reduce or remove unnecessary things that make our interface complicated while keeping useful information that is really needed, which may simplify the process of handling tasks.