Add the difficulty of varied practice

Change the context, examples, and conditions instead of drilling identical reps.

Why it works

Practicing under varied conditions is harder than repeating identical ones, but it builds a more flexible, generalizable skill. Variation forces the brain to extract the underlying principle rather than a single context-bound routine, so the learning transfers to new situations the test — and real life — actually present.

How to do it

1. Vary the examples, settings, and surface features across practice attempts.
2. Resist the smoother feeling of drilling one fixed version repeatedly.
3. Practice in conditions closer to where you will need to perform.

Evidence

Studies on variability of practice find that varied conditions, though they depress immediate performance, tend to improve transfer and retention compared with constant, repetitive practice — a classic desirable difficulty. The effect spans domains: Kerr & Booth (1978) found varied motor practice outperformed fixed practice, and Rohrer & Taylor (2007) showed that interleaving different problem types improved later math performance. (rct)

Variation helps transfer but can hinder early acquisition; beginners may need some consistent practice to build a base before variability pays off.

Sources

• Kerr, R., & Booth, B. (1978). Specific and varied practice of motor skill. Perceptual and Motor Skills, 46(2), 395–401.
• Rohrer, D., & Taylor, K. (2007). The shuffling of mathematics problems improves learning. Instructional Science, 35(6), 481–498.

Common mistake

Drilling the exact same problem or scenario over and over because the fluency feels like progress, building a brittle skill that collapses when conditions change.