During the past ten years, I have worked with many children who use augmentative and alternative communication (AAC) systems. An AAC system is a communication tool that replaces or supplements spoken language. A specific AAC system is often referred to as an AAC device. Some AAC devices are downloaded to tablets like an iPad, running software that displays picture symbols for words, such as basic nouns, verbs and adjectives. For example, TouchChat produces AAC software for tablets.
Less complex AAC devices may combine voice output with static picture overlays instead of dynamic screens. For example, GoTalks sells devices with picture symbols printed on laminated sheets, which produce sound when the symbols are touched. Some systems do not involve voice output at all. For example, in PECS, children can communicate by handing individual pictures to a communication partner.
The Benefits of AAC and the Importance of Caregiver Training
If children are nonverbal or have limited verbal skills, the use of AAC can significantly improve their ability to communicate, which in turn decreases their frustration, builds connection with others and improves their language development and spoken language abilities. This important tool has so much potential to impact a child’s development, but unfortunately it’s often briefly employed and then discarded by caregivers who are not properly trained in its implementation.
Particularly during my work in the school setting, I saw many AAC devices handed to parents and teachers without proper training. Those devices often sat in a closet or in a student’s desk, unused. Perhaps some caregivers viewed the devices as resulting in too much work for little payoff. Or sometimes people worked hard on implementing the device but saw little progress or interest from students.
Effective Prompting Techniques
There are many ways to ensure that children make steady gains when using AAC devices, but one important principle that is central to AAC implementation is to focus on the quality of the caregivers’ prompting. By prompting, I mean an intervention (e.g., pointing, questioning, gesturing) that encourages the use of a specific skill. For example, we may prompt our child to wash her hands by saying “Didn’t you forget something?” In the same way, we may prompt a child to use AAC by pointing to a symbol on her device.
How do we know what kind and what level of prompting will be most effective? A recent study on the implementation of effective prompting strategies for children using AAC employed a “least to most” (LTM) prompting procedure (Finke et al., 2017). The LTM prompting procedure involves five distinct “levels” of prompting.
The least invasive prompt is the “expectant delay,” where we wait for a child to initiate communication after a natural cue. For example, we may pause when reading a book and wait for a child to make a comment or request. If the child does not respond, we use a verbal prompt (e.g., “What’s happening?”), and then a verbal prompt and a model at the next level (e.g., “What is she doing?….She’s sleeping”). If the child still does not respond, we provide a verbal cue, a verbal model and a graphic model by selecting the appropriate symbols on the device. Finally, if all of this is unsuccessful, we use hand-over-hand prompting to help the child touch the appropriate symbols.
Why is the “Least-to-Most” Technique Effective?
If we initially provide a maximum level of prompting when training new skills, children become dependent on the prompting and may lose motivation to communicate on their own. Children with language impairments need time to process information and initiate interactions. By using a LTM prompting strategy and allowing waiting time between prompting levels, we maximize our chances that the child will communicate independently. LTM prompting also ensures that the child will ultimately be successful with any given task. If the child makes an error, we continue to add additional support until the target behavior is achieved.