Stimulus Control Research and Practice: Considerations of Stimulus Disparity and Salience for Discrimination Training

Halbur et al. (2021) wrote a how-to guide, not an experiment.

They pulled together old lab work on stimulus disparity and salience.

The goal: give BCBAs rules for picking training materials that teach faster.

No new data—just clear rules.

Make the target feature the only thing that differs across cards (disparity).

Make that feature pop—bright color, big size, loud voice—so the learner notices (salience).

Wolchik et al. (1982) showed pigeons needed high salience or learning never started; Halbur turns that into a checklist you can use at the table.

Attwood et al. (1988) proved that stripping extra shapes off flash-cards for preschoolers speeds acquisition; Halbur folds that tactic into the disparity rule.

Rose et al. (2000) moved the idea into assessment—painting FA rooms different colors made results clearer for half the clients; Halbur’s rules apply the same logic to teaching trials.

Axe et al. (2021) warns us not to call every instruction an “SD” unless control is proved; Halbur’s paper gives the tools (disparity + salience) to build real stimulus control so the label fits.

Next time you build a discrimination program, run the two-step test: (1) Is the target dimension the only thing that changes? (2) Would a distracted learner still spot it? If either answer is no, tweak the materials before the first trial. These small front-end fixes can save hours of error correction later.