Cobra Effect · Learning and memory
Cognitive load
The mind can juggle only a few new things at once.
7 cards, read aloud in 2:19, with a test and sources.
The slide holds 40 lines, three arrows and a picture.
The lecturer talks over the top of it. The room reads, listens and takes in neither. Half an hour later almost nothing has stuck.
Working memory is tiny. That is the whole problem.
You can hold only a few new things in mind at once, and only for seconds. Everything you learn has to pass through that narrow gate. Fill it with the wrong traffic and nothing gets through.
1988. John Sweller gives the gate a name.
Cognitive load is how much of that gate a task is using up. Some of the load is the material itself, and there is no avoiding it. Some of it is only the way the material was laid out, and that part is the teacher’s doing.
Clutter has a price that nobody sees.
A diagram on one page and its explanation on the next makes the reader hold one while hunting for the other. Reading a sentence aloud while the same sentence sits on the board spends the gate on a duplicate. Every hunt is load spent on nothing at all.
The strongest finding here is almost insulting in its simplicity.
Beginners learn more from studying a worked example than from struggling with the problem. Sweller and Cooper showed it with algebra students in 1985. Searching for a method uses the gate. Being shown the method leaves room to learn it.
This flips as people get better.
What helps a beginner starts to bore an expert, and then starts to hold them back. Once the method is known, the example is clutter and the struggle is where the learning is. Support has to fade, or it turns into a crutch.
What to do before you teach anybody anything.
Cut everything that is not the thing being learned. Put each picture and its explanation next to each other. Show one worked example before you ask for the first attempt. Then say less, and wait.
Sources
- Cognitive load, Wikipedia. The theory, the three kinds of load and the arguments about them. For the original, search for Sweller, 1988, Cognitive load during problem solving.
- Cognitive Load Theory, John Sweller, Paul Ayres and Slava Kalyuga, 2011. The field written up by the people who built it, including the worked example result and how it reverses as learners gain expertise.
- Worked-example effect, Wikipedia. The single most studied result in this area, with the 1985 algebra study and what happened when it was tried on other subjects.
Nearby ideas
- Chunking. Experts see patterns where beginners see pieces.
- Desirable difficulties. The practice that feels hardest is often the practice that sticks.
- Dual coding. Words and pictures together stick better than either alone.
- The illusion of competence. Feeling familiar with material is not the same as knowing it.
- The generation effect. Trying to produce an answer first makes it stick, even when you are wrong.
- The learning styles myth. Matching lessons to a preferred style does not improve learning.
- Sleep and consolidation. Sleep is when the day’s learning gets filed away.
- The spacing effect. Spread your study out over time and it lasts far longer.