Bolt Series · Human Performance Calibration · Article 21
Practice can change two things, not one
We usually think practice has one job:
Make me better.
That is certainly important.
A student practises algebra and becomes better at algebra.
A sprinter practises starts and becomes better at starting.
A pianist practises a difficult passage and becomes more fluent.
But repeated practice can also change something else:
How accurately I know what I can do.
Those two changes are related.
They are not the same.
A learner can improve before their self-estimate catches up
Imagine a student who has struggled with fractions for years.
Then something changes.
The teaching becomes clearer.
The student practises retrieval rather than rereading.
Errors are diagnosed instead of merely corrected.
Performance rises.
But every time a fraction appears, the student still thinks:
“I’m bad at fractions.”
The capability has changed.
The internal estimate has not changed at the same speed.
This is one reason underestimation can persist even after improvement.
The opposite can happen too
A student practises twenty questions that all look almost identical.
By Question 20, everything feels easy.
The learner thinks:
“I have mastered this.”
Then the examination changes the surface of the problem.
The learner cannot identify the method.
Practice has increased familiarity and perhaps fluency on one form of the task.
But the learner’s estimate has expanded further than the demonstrated capability.
Again, two curves have separated.
This gives us two learning curves
One curve asks:
How is performance changing?
The other asks:
How accurately is the learner tracking that change?
A student can improve on the first curve without improving equally on the second.
Or the student can become more certain without sufficient evidence that the first curve has moved.
Good education needs to watch both.
Practice tests show why this matters
Research in an introductory biology course examined whether practice testing improved both exam performance and students’ ability to predict their exam scores.
Students who voluntarily completed a practice test tended, on average, to perform better and to show better calibration.
But the improvement was not uniform.
Many lower-performing students still substantially overestimated their knowledge despite receiving practice-test feedback, while some higher-performing students became underconfident.
That is exactly why we should not assume:
Practice happened → therefore self-knowledge automatically became accurate.
Practice can provide the evidence needed for calibration.
The learner still has to use that evidence well.
The timing of self-judgement matters too
One of the more robust findings in metacognitive research is the delayed judgement-of-learning effect.
A meta-analytic review found that predictions about future memory tend to become more accurate when people make the judgement after a delay rather than immediately after studying.
Why might that happen?
Immediately after studying, the material is still present and familiar.
That feeling can be mistaken for durable learning.
After a delay, the learner has to sample something closer to the future retrieval problem.
The judgement is now being made from better evidence.
A self-estimate improves when the cue used to make the estimate becomes more diagnostic of the real task.
Sport has the same two-learning-curve problem
An athlete can physically improve while still misjudging readiness.
Or an athlete can feel excellent in training while competition exposes a remaining weakness.
This is one reason high-performance sport repeatedly combines practice with monitoring.
Training changes the athlete.
Times, video, coach observation, perceived exertion and competition help update the model of the athlete.
A 2023 review of self-regulated sport practice describes expert practice as involving processes such as planning, monitoring and reflection across substantial periods of athlete-led as well as supervised practice.
That is important.
The athlete is not only performing repetitions.
The athlete is learning how to read what those repetitions mean.
A good practice session should leave two receipts
For education, this suggests a simple improvement.
After practice, record two things.
- Performance receipt: What could I actually do independently?
- Calibration receipt: Did my prediction of what I could do match what happened?
For example:
“I thought I could solve 8 out of 10 unfamiliar quadratic questions without help. I solved 5. I overestimated transfer even though routine questions felt easy.”
That learner has acquired more information than someone who merely records:
“5/10.”
The first learner can update both skill and strategy.
Do not confuse better calibration with better capability
There is an important safeguard.
A student can become very accurate at saying:
“I will probably get 45%.”
Then get 45%.
That is better calibration.
It is not yet better Mathematics.
The purpose of calibration is not to admire an accurate self-description.
It is to make the next action better.
If I know exactly where I am weak, I can practise the right thing.
Then capability changes.
Then my estimate must update again.
This creates a moving target
Calibration is not something you achieve once.
If learning works, the person being calibrated keeps changing.
Yesterday’s accurate estimate can become today’s underestimate.
Yesterday’s strength can become insufficient at a higher level of difficulty.
A new environment can reveal a capability that old tasks never tested.
So the learner must repeatedly do two jobs:
- change through learning;
- update the internal map as that change occurs.
Why this matters for education
We want students to improve.
But we also want them to recognise improvement when it is real, recognise weakness when it is real, and avoid confusing familiarity, effort or emotion with proof.
Practice should change what you can do. Good practice should also improve your ability to tell what changed.
That second outcome is easy to miss because it does not always appear on the report card.
Yet it may determine whether the learner knows what to do with the next hour of study.
eduKate Sengkang 