An evaluation of repeating the discriminative stimulus when using least-to-most prompting to teach intraverbal behavior to children with autism.

Kodak et al. (2013) asked a simple question. When you use least-to-most prompting to teach intraverbals, should you repeat the question each time you prompt?

They worked with children with autism. Each child got the same intraverbal task two ways. In one condition the adult repeated the question every prompt. In the other condition the adult gave the question only once.

An alternating-treatments design let the team track how fast each child learned under the two styles.

Kids learned the intraverbal answers no matter what. Repeating the question did not cut the number of trials. It also did not help the child master the skill faster.

In short, the extra repetition gave zero efficiency bonus.

Farber et al. (2017) also tweaked how stimuli are shown during prompting. They added a quick identity-matching step to help kids notice all parts of a display. Their change worked. Tiffany’s change did not. The difference is that Farber added a new teaching piece, while Tiffany only repeated an old one.

Francis et al. (2020) compared another prompt-fade tactic, progressive time delay. Their tactic sped up learning. Tiffany’s tactic stayed flat. The lesson: some prompt changes matter, others just burn time.

Miranda-Linné et al. (1992) used the same alternating-treatments design with kids with autism. They found that discrete-trial beat incidental teaching for speed at first, but incidental teaching won later. Tiffany’s null result lines up with the idea that small procedural tweaks often wash out in the long run.

You can stop repeating the discriminative stimulus during least-to-most prompting. Save your breath and keep the session moving. The child will still learn the intraverbal. Use the extra seconds for more trials or for reinforcement instead.