Fixed-ratio and fixed-interval schedule control of matching-to-sample errors by children.

The team asked children to play a picture-matching game on a computer. After each correct match, the kids earned tokens on different schedules. Some kids got a token after every few correct matches (fixed-ratio). Others got a token after a set time (fixed-interval). A third group got tokens at random times (variable schedules).

The researchers counted how many wrong matches each child made right after getting a token. They wanted to see if the schedule changed when errors happened.

Fixed-ratio and fixed-interval schedules made error patterns predictable. Kids made more wrong matches right after they got a token. Then their accuracy improved until the next token came. Variable schedules did not create this burst of errors.

In short, steady schedules produced steady mistake patterns. Random schedules did not.

Hamm et al. (1978) ran a similar lab study with adults. They also saw that fixed-interval schedules create more variable behavior than fixed-ratio. Together, the two papers show that schedule type controls both errors and response style across ages.

Clarke et al. (1998) moved the same idea into a classroom. Teens with severe ID earned tokens on fixed-ratio while doing vocational tasks. Stereotypy dropped more than on variable-interval schedules. The classroom data extend the lab finding: fixed-ratio keeps behavior cleaner.

Mintz et al. (1966) first spotted the effect in pigeons. Visual cues that signaled ratio progress cut matching errors. Tracey et al. (1974) later proved the same schedule control happens in children, bridging animal and human work.

If you use token boards or point systems, expect a brief spike in errors right after each payoff. That is normal schedule control, not lack of skill. To smooth the dip, you can shorten the ratio, add a brief prompt, or switch to a variable schedule for a few trials. Knowing the pattern lets you plan for it instead of fighting it.