Sequencing instructional tasks. A comparison of contingent and noncontingent interspersal of preferred academic tasks.

Five preschoolers with language delays sat at a tiny table. The teacher placed two kinds of cards in front of them: hard new tasks and easy picture games the kids liked.

Some days the kids had to finish the hard card first to touch the fun card. Other days the fun card just showed up, no matter what. The team flipped the order each day to see which way made the kids get more answers right.

When the fun card waited for a correct answer, three kids suddenly nailed the hard work. One child did fine either way. The last kid only perked up when the teacher kept switching the routine itself.

Bottom line: most tots worked better when the treat was locked behind a right response, but one-size-fits-all failed for two kids.

Knutson et al. (2019) later asked, "What if we drop the fun cards completely?" They found kids with autism mastered brand-new skills fastest when every trial was new—no mastered tasks mixed in. Their 0:1 ratio result sharpens the 2003 mixed picture: skipping interspersal can speed acquisition.

Charlop et al. (1992) ran an earlier version with autistic children and edible treats. They saw the same trend—save the good stuff for correct acquisition trials—laying the groundwork for the 2003 preschool test.

Bacon-Prue et al. (1980) showed the idea works across ages: mixing old spelling words with new ones helped older students with ID learn faster and remember longer. Together, these studies say interspersal helps, but the best recipe changes by kid and by goal.

You already use first-then boards. This paper says check who really needs the then. Start with contingent access—make the fun task depend on one correct response. If accuracy jumps, stay there. If it flat-lines, try non-contingent or shake up the order. One quick assessment Monday can save you weeks of slow gains.