A comparison of time delay and system of least prompts in teaching object identification.

The team compared two ways to teach object names to learners with severe intellectual disability.

One group got progressive time delay. The teacher waits a little longer each time before giving the answer.

The other group got the system of least prompts. The teacher gives bigger and bigger hints until the child is right.

Both groups learned the same set of household objects like cup, spoon, and shoe.

Both methods worked. Every child reached the mastery line.

Time delay got them there faster and with fewer wrong answers. It also took less teaching time overall.

Durand et al. (1990) ran a direct replication and saw the same edge for time delay. They also showed that single static cues, like a colored border, can wreck earlier learning.

Cihon et al. (2020) looks like a contradiction. Their RCT with kids with ASD found no real speed gap between time delay and least prompts. The difference: they used tacts, not object labels, and ran a group design.

Taber-Doughty (2005) extends the story. High-schoolers with ID learned fastest when they could pick their own prompt style, even if it was least prompts. Choice, not the prompt itself, drove the gain.

If you teach object names to learners with severe ID, start with progressive time delay. You will hit mastery sooner and see fewer errors. Keep cues simple; skip extra colors or borders that can block generalization. If the learner is older or has ASD, add choice or expect smaller speed gains. Either way, track errors and minutes — the clock and the mistake count tell the real story.