Cognitive Load

Cognitive load, folks. In our digital worlds, it’s a thing. Short-term memory, the one you’re using while you read this, can hold up to 10 items, give or take.

If you add organising, contrasting, or comparing, that number shrinks to around 2 or 3. Short-term memory has two main inputs–visual and auditory. Add touch, and you’ve got a third; visual and auditory are the ones we use most, especially when we’re teaching.

Long-term memory is unlimited. It contains everything you’ve ever learned. It’s used to make sense and give meaning to our world. Knowledge in long-term memory is stored as schemata.

When you drive your car to school, your brain accesses your “car-driving schemata.” It holds everything you know about driving: road rules, speed/time/distance relationships, estimation skills, sensory inputs/outputs, balance and coordination.

It is a vast body of knowledge, yet we manage it without a second thought. Throw in a distraction, though, and we struggle—kids arguing in the back seat, the driver who cuts you off, and the phone.

You hit your cognitive load limit.

Now, translate that thought to how you present learning to students. How many of them reach their cognitive load limit and can’t absorb any more? They switch off or react in a way you hadn’t planned for.

Here’s a thought to end with: in a typical classroom question-and-answer session, the student who answers the question may be the only one in the class with any insight into the issue being questioned. We’ll dig deeper next time.