Teaching children with autism spectrum disorder to mand for information using "which?".

We examined a procedure consisting of a preference assessment, prompting, contrived conditioned establishing operations, and consequences for correct and incorrect responses for teaching children with autism to mand "which?" We used a modified multiple baseline design across 3 participants. All the children learned to mand "which?" Generalization occurred to the natural environment, to a novel activity, and to a novel container; the results were maintained over time.