The Effects of Contingency Contracts on the Correct Use of Punctuation Marks in Elementary Students With Learning Disabilities

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German Grade 3 pupils with learning disabilities, aged 8, 9 and 9

ABC multiple-baseline single-case design across three children, 12 daily probes, with punctuation accuracy measured in free writing. Recorded not as evidence that punctuation is teachable but as evidence about what the deficit actually IS at this age. No instruction was delivered: the intervention was a contingency contract - a behavioural agreement rewarding correct punctuation. Interrater agreement 96%. Single-case, n = 3, no control group, so it carries no weight as an effect estimate.

Percentage of punctuation marks used correctly in free writing: one child moved from 0.00 at baseline to 88.85 and 81.48 in the two intervention phases; a second from 13.35 to 87.95 and 90.95. A jump of that size within days, produced by a reward contract and no teaching whatsoever, means the children already possessed the punctuation knowledge and were not deploying it. That is a PERFORMANCE deficit, not a knowledge deficit, and it is the single most useful thing in the study: at age 8 to 9, at least for some children, the binding constraint on conventions in writing is attention and habit under composition load rather than not knowing the rule. Grünke's own literature search for contingency contracts applied to punctuation returned two prior hits in the entire indexed literature, both single-case.

Not applicable - within-subject design. The corresponding limitation is that nothing separates the contract from practice, expectancy or attention.