Teaching Early Numeracy Skills Using Single Switch Voice-Output Devices to Students with Severe Multiple Disabilities (summary)



There is limited research evidence into teaching students with severe disabilities, possibly due to the difficulties imposed by their limited communication. The research that there is tends to focus on literacy and communication rather than maths or numeracy skills. The authors of this paper therefore chose to investigate the ‘effect of a systematic instructional package with individualized adaptations on the acquisition of numeracy skills’. The research involved three children with severe multiple disabilities and complex communication needs (CCN).

What did they do?

Three children, one aged 9 and two aged 11 took part in the study. All had multiple disabilities including severe intellectual disability, one had no vision and did not respond to visual stimuli. All of the children demonstrated some early receptive language skills and used a variety of simple augmentative and alternative communication (AAC) systems, including single switch voice-output systems, expressively.

The intervention took the form of the teacher being given two hours of training and then delivering five different maths lessons a minimum of 3 times each either to individuals or groups of two pupils. The lessons followed a scripted ‘maths story’ and each had 12 early numeracy skills objectives built in. The use of maths stories gave the children opportunities to perform maths skills such as rote counting, identifying numbers, making sets etc. The children actively responded in different ways; using yes/no switches, number-lines, touching story –related resources etc.

The researchers carried out baseline assessments prior to the intervention starting and probes to monitor progress at various points throughout the intervention period.

Only one of the children completed participation in all 5 scripted lessons, one took part on 4 and the third only 2.

What did they find?

All of the participants showed significant increase in scores from the baseline to the final assessment, indicating improvement in their ability to demonstrate early numeracy skills within the lessons. The teacher also gave very positive responses when interviewed about her views of the intervention. She indicated that she would use the same approach again with other pupils despite the amount of time needed to adapt materials to make them accessible and to provide voice output devices for participants.


The results indicate that the ‘systematic instructional package with individualized adaptations … was effective for teaching … targeted early numeracy skills’. However the use of single switch voice-output systems was limiting, only enabling responses to questions not supporting comments, questions or voicing of opinions. Informally the participants were all observed to use other non-verbal communication to convey a range of meanings in addition to activating switches.

The authors support the idea that AAC and other assistive technology helps improve student outcomes and increase opportunities to learn and show their learning.

The participants’ communication difficulties posed challenges for teaching and learning that were not related to the curriculum. The authors identify that communication development activities should be integrated into academic lessons and other activities rather than being taught in isolation. Without AAC it is concluded that the children would not have been able to actively engage in maths lessons and demonstrate their learning.


One of the three participants had very limited interventions and still showed significant improvement form her baseline score, however it is not possible to know whether this rate of improvement would have been maintained with further intervention. This child was visually impaired (VI) and needed to develop strategies for making choices from a range of options; the need for involvement of VI specialist teachers working with other specialist teachers is recommended as important.

The amount of time needed to prepare and adapt curriculum support materials to make them accessible is identified as a limitation of this type of intervention, but once prepared the resources could be used over a number of academic years.

This research only considered children who were taught in special school provision and did not include any students with disabilities educated in mainstream settings.

Things you may want to look into:

Microswitch Technology for Enabling Self-Determined Responding in Children with Profound and Multiple Disabilities: A Systematic Review

Where are teachers' voices? A research agenda to enhance the communicative interactions of students with multiple and severe disabilities at school

Added to site May 2016