Least-to-Most Prompting
What is it?
Least-to-most prompting is a hierarchy of support used to teach a skill, beginning with a natural cue. Subsequent prompts are provided in a sequence from the least amount of support, such as providing an expectant pause, to the highest level of support, such as physical assistance.
How can least-to-most prompting be used with AAC to promote vocalisations?
In the context of promoting vocalisations using AAC, the hierarchy may be as follows:
Expectant pause.
Verbal prompt.
Verbal model.
Graphic model.
Request a response.
Hand-over-hand prompting.
An example of how to implement this with an SGD user is:
Ensure the corresponding vocabulary of a series of storybooks is available on the AAC user's device, then allow them to choose a storybook to read together.
Select a goal based on their skill level, for example, to communicate a two-symbol message related to the book. Remain on the first double-page spread until completed. If the learner attempts to turn the page before this is achieved, just tell them that you need to finish talking about the current page first.
Introduce increasingly more intrusive prompts until the learner successfully produces a message related to the book according to the predetermined goal (e.g., a multi-symbolic message).
For example:
Expectant pause: Provide a short time delay to offer the learner an opportunity to initiate communication about the story.
Verbal Prompt: Introduce a verbal prompt, such as "What is happening?" and provide another time delay.
Verbal Model: Provide the same verbal prompt, followed by a verbally modelled answer. Such as, "What is happening?" followed by "I see the cat is sleeping."
Graphic Model: Following the verbal prompt and verbal model, provide a graphic model by using the SGD to select the appropriate symbols, such as "cat sleeping."
Request a Response: Repeat steps 1 to 4 and follow with an invitation to respond, such as "Now you try."
Hand-over-hand prompting: Repeat steps 1 to 5, and then provide a physical hand-over-hand prompt by guiding the learner's hand to select the appropriate symbols, such as "cat sleeping."
If the goal is to produce multi-symbolic communication, and the learner provides a single symbol answer, gently encourage them to expand on their response. If this does not produce further relevant symbols, re-engage in the least-to-most prompting procedure.
When the learner successfully meets the communication goal, positive reinforcement could be given through positive and affirmative feedback, such as "That's right, the cat is sleeping." This process can be repeated as you move through the storybook.
Some guidelines for implementing least-to-most prompting effectively:
Least-to-most prompting can be helpful to develop the learner's skills further; however, if it is a new skill, you may consider using most-to-least prompting instead. When using prompts, we need to be mindful of encouraging the AAC user's independence and be careful that they do not become prompt-dependent by over-prompting them. It is important to pause and provide enough time for the learner to process and respond.
When it comes to prompt selection, there are two primary considerations:
Identify a prompt that the learner will consistently respond to.
Fade out the need for prompting over time so that the AAC users learn to communicate without being prompted.
References
Finke, E.H., Davis, J.M., Benedict, M., Goga, L., Kelly, J., Palumbo, L., Peart, T., & Waters, S. (2017). Effects of a Least-to-Most Prompting Procedure
on Multisymbol Message Production in Children With Autism Spectrum Disorder Who Use Augmentative and Alternative Communication.
American Journal of Speech-Language Pathology, 26(1), 81-98. https://web.p.ebscohost.com/ehost/pdfviewer/pdfviewer?vid=0&sid=4e2ecbf6-efd4
4816-9674-6ad7aba0bf8c%40redis
Sigafoos, J., van der Meer, L., Schlosser, R.W., Lancioni, G.E., O'Reilly, M.F., & Green, V.A. (2016). Augmentative and Alternative Communication
(AAC) in Intellectual and Developmental Disabilities. In Luiselli, J.K., & Fischer, A.J. (Eds.), Computer-Assisted and Web-Based Innovations in
Psychology, Special Education, and Health (pp.255-285). Elsevier. http://doi.org/10.1016/B978-0-12-802075-3.00010-3.