A comparison of fixed and repetitive models to teach object imitation to children with autism
Use the same fixed model across trials when teaching object imitation to preschoolers with autism — it’s usually faster.
01Research in Context
What this study did
Halbur et al. (2023) asked a simple question: when you model how to copy an action with a toy, should you do it the same way every time or switch it up?
They worked with preschoolers with autism. Each child got both kinds of modeling in an alternating-treatments design.
Fixed modeling meant the adult always stacked the blocks the exact same way. Repetitive modeling changed the block pattern each trial.
What they found
In 10 out of 16 head-to-head comparisons, kids learned faster when the model never changed. Two comparisons favored the changing model, and four showed no difference.
The takeaway: sticking with one clear model is usually the quicker path to mastery.
How this fits with other research
Deshais et al. (2020) ran almost the same study and got the opposite winner — repetitive models came out on top. The two papers form a direct replication with flipped results.
The clash looks real, but the kids and methods differed slightly. Halbur used an alternating-treatments setup; Deshais used a simpler single-case design. Small details can swing the winner.
Bloh et al. (2025) also used an alternating-treatments design, but compared human versus animated video models. They found individual preference matters — a reminder that the "best" model can vary by learner.
Why it matters
When you teach object imitation, start with a fixed model. It’s easy to do and Halbur’s data show it wins more often than not. If the child stalls, try switching to a varied model — Deshais proved that can work too. Track the data and let the learner’s progress pick the final strategy.
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02At a glance
03Original abstract
A well-established imitative repertoire can facilitate the acquisition of functional communication, social behaviors, and observational learning. Although early intensive behavioral intervention programs for young children with autism incorporate imitation training, learners with autism may exhibit difficulties in acquiring an imitative repertoire. Few studies have evaluated the types of models responsible for acquisition when teaching imitation to children with autism. A preliminary evaluation with fixed and repetitive model targets suggested that children with autism may acquire imitation more rapidly when taught with repetitive models (Deshais & Vollmer, 2020). The purpose of the current study was to compare the rates of acquisition when teaching with repetitive and fixed models for six children with autism. The findings suggested that (a) fixed models resulted in the most efficient acquisition for 10 of 16 comparisons, (b) fixed and repetitive models had similar efficacy for four comparisons, (c) and the repetitive condition was most efficient for two comparisons.
Journal of Applied Behavior Analysis, 2023 · doi:10.1002/jaba.993