Comparison of Acquisition Criteria Applied to Individual and Sets of Tacts: A Systematic Replication

Chang et al. (2024) asked a simple question: should we master each tact one by one or wait for the whole set to hit 100%?

They ran an alternating-treatments design with four learners. One condition used Operant Analysis—each picture had to score 90% across two sessions. The other used Set Analysis—the full set had to hit 100% before any item was considered mastered.

The team counted how many teaching trials each path needed and checked if the words stayed solid two weeks later.

Operant Analysis won every time. Every learner reached mastery in fewer trials when each word had to pass on its own.

Maintenance stayed about the same for three of the four learners, so the faster route did not cost long-term recall.

Wong et al. (2022) and Cordeiro et al. (2022) already showed the same edge for single-item mastery with sight words and tacts. Chang’s team narrows the field to pure tact training and still sees the same win, tightening the pattern.

Zhi et al. (2023) used Operant criteria too and found tacts stuck just as well with bigger sets, but they did not test Set Analysis. Chang closes that loop by showing the criteria matter more than set size.

Kodak et al. (2020) looks like it disagrees—those authors say bigger sets (6–12 items) speed acquisition. The clash clears up once you see Kodak used set-level mastery while Chang used item-level mastery. Big sets help only if you wait for the whole group to pass; switch to per-item scoring and you finish faster no matter the set size.

If you still wait for every card in the box to hit 100%, you are running extra trials you do not need. Flip to Operant Analysis: score each picture alone at 90% across two checks, then move it to maintenance. You will free up table time for new targets without risking the old ones.