Examination of a Modified Incremental Rehearsal Approach to Explore Causal Mechanisms.

The team tried a new twist on incremental rehearsal (IR) for math facts. They called it Shuffle IR, or ShIR.

Instead of lining up known cards in the same order every time, they shuffled the deck. Kids still saw one new fact and nine old ones, but the old facts came in random order.

Six neurotypical fourth-graders took part. The researchers compared ShIR, regular IR, and a no-practice control in a single-case design.

Both IR and ShIR beat the control. Kids learned new facts faster when they practiced than when they did not.

Retention scores split right down the middle: three kids kept more facts with ShIR, three with standard IR.

Maintenance told a clearer story. Most students held onto the facts longer after ShIR sessions.

Singh et al. (1991) looked at shuffling spelling words thirty years earlier and saw zero bonus. Straight rehearsal worked just as well as mixed order. The new math study flips that outcome. The difference: N et al. measured next-day spelling recall, while E et al. tracked math facts for weeks. Quick spelling tests may miss the long-term boost that random order gives.

DeRoma et al. (2004) also chased durable learning. They showed that copy-cover-compare beats picture matching for keeping sight words. ShIR uses the same logic: tweak the practice format, not the content, to make memories stick.

Bennett et al. (1998) found that immediate self-correction helps fourth-graders keep multiplication facts. ShIR adds another easy layer: shuffle the known stack before each round. You can combine both tricks—correct right away and shuffle—for a low-cost power-up.

You already use IR because it is quick and kids like it. ShIR needs no new materials—just mix the flash cards before each round. If your learner’s data show fading math facts a month later, try ShIR. Track maintenance weekly; if the curve stays flat, you have a winner with almost zero prep.