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Feature-Matching in AAC Assessment: Linguistic Features

Updated: Jun 6, 2023

Have you seen our previous posts on Feature-Matching in AAC Assessment?

  • We’ve discussed voice features, access features, and portability/positioning features. Learn more here! Forbes AAC Blog

Feature-matching is a systematic process in which an AAC user’s strengths and needs are matched to available tools and strategies (Shane & Costello, 1994). This week's blog post aims to highlight the many different linguistic features to consider when recommending an AAC system for a user!

There are MANY systems available for AAC users to meet their unique needs.

  • These systems are organized in different ways and they present language in different ways.

  • Systems can provide users with simple language for those who are emerging communicators all the way up to more complex language for those who are able to put together longer messages.

How do we decide which linguistic features to trial and recommend? According to Locast and Marx (2016), linguistic features to consider include:

  • Availability of pre-created pagesets

  • Language complexity

  • Symbol organization

  • Display settings

Pre-Created Pagesets

  • Many language systems provide pagesets that are already created. For example, our WinSlate speech-generating device comes with the CoreWord language system with three pre-created pagesets - CoreWord 6, CoreWord 20, and CoreWord 40.

  • The CoreWord language system provides a combination of core language, fringe vocabulary, and banks of key phrases. This approach to AAC promotes natural communication while allowing users to express themselves as efficiently as possible in all environments with all communication partners.

  • Pre-created pagesets available allow for immediate access to language. There are different features offered through pre-created features that can be matched to an AAC user and what they need. Features such as syntactic predictability, Fitzgerald color coding, and use of motor learning principles should be considered in the evaluation.

Language Complexity

  • Language can be presented in many different ways through AAC. For emergent communicators, it's common to start with the use of single-meaning picture symbols. With communicators who are literate, they can use text-based methods.

  • It's also important to consider the layout of an AAC system and how it allows the user access to core vocabulary and fringe vocabulary. Many symbol-based communication systems are set up to allow the AAC user to quickly access core vocabulary while allowing the user to be able to navigate to other pages with personalized, fringe vocabulary.

Symbol Organization

  • Symbol organization on an AAC system affects the individual's ability to communicate effectively and efficiently (ASHA, n.d.).

  • Organization may change over time based on the user’s changes in skills, abilities, and contexts (Beukelman & Light, 2020).

  • Types of organization include activity grid displays, taxonomic grid displays, semantic-syntactic grid displays, pragmatic organization dynamic displays (PODD), and chronological grid displays (Beukelman & Light, 2020).

  • Activity grid displays are organized based on a user's day such as a specific routine or activity while taxonomic grid displays are organized based on semantic categories. Semantic-syntactic grid displays are organized based on parts of speech and syntax.

  • Visual scene displays (VSDs) are another display option! These are integrated scenes of meaningful and motivating events (Blackstone, 2004).

  • For text-based communicators, the keyboard can be customized based on their preference. For example, do they prefer a QWERTY keyboard or an alphabetical keyboard?

Display Settings

  • How a system allows for customization of the display settings is also important to consider. There are different modifications that can be done to maximize the user's efficiency with a system! Hiding buttons, changing the size of the message display window, and other features should be addressed.

Another important point! Feature matching should consider an individual’s current and future AAC needs (Gosnell et al., 2011).

  • That means the system must be able to adapt to the user's changing communication abilities.

  • For example, an individual who starts communicating using a symbol-based communication system may learn to read and write. At that point, they may benefit from a text-based communication system!

Want to use the feature-matching process in your own clinical practice? Try these feature-matching chart from Forbes AAC!

Another great resource to check out? This resource from the Communication Aids and Systems Clinic (CASC) at the University of Wisconsin Hospital and Clinics created by Abygail Marx, M.S., CCC-SLP and Mary Locast, OTR.


  • American Speech-Language-Hearing Association (n.d.). Augmentative and Alternative Communication (Practice Portal).

  • Beukelman, D. R., & Light, J. C. (2020). Augmentative & alternative communication: Supporting children and adults with complex communication needs (5th ed.). Brookes.

  • Gosnell, J., Costello, J., & Shane, H. (2011). Using a clinical approach to answer “what communication apps should we use?” SIG 12 Perspectives on Augmentative and Alternative Communication, 20(3), 87–96.

  • Locast, M. & Marx, A. (2016). AAC Feature Matching Overview [Presented at The American Academy for Cerebral Palsy and Developmental Medicine AACPDM) Annual Meeting]. Accessed from: (June 8th, 2022).

  • Shane, H., & Costello, J. (1994, November). Augmentative communication assessment and the feature matching process. Mini-seminar presented at the annual convention of the American Speech-Language-Hearing Association. New Orleans, LA.

Katie Threlkeld, M.S., CCC-SLP is a licensed, ASHA-certified speech-language pathologist and the Educational Program Developer at Forbes AAC. She has over eight years of experience in AT and AAC assessment and treatment with both the pediatric and adult populations. Katie has presented at the state and national level on AAC topics and she has University teaching experience at the undergraduate and graduate level.

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