[Source: Speech Dudes]
When developing a vocabulary set for an augmented and alternative communication (AAC) system – or indeed when deciding on what vocabulary to teach anyone – one of the most fundamental of measures you can use is frequency count; how often is a word used in a language? No-one can predict with 100% accuracy which words will be “best” for an individual, but if you’re going to take bets, you’re pretty safe to assume that words such as that, want,stop, and what are going to be used by everyone from ages 2 to 200. By the same token, you’d not be missing much if you didn’t spend too much time on words likeambidextrous, decalogue, and postilion .
In the field of AAC, this type of high frequency vocabulary that is used (a) across populations and (b) across situations is referred to as core vocabulary and it’s often contrasted with the phrase fringe vocabulary, which refers to words that are typically (a) low in frequency and (b) specific to isolated activities or situations. For a refresher on core and fringe – and an introduction to keyword vocabulary – check out my article entitled Small Object of Desire: The Monteverde Invincia Stylus fountain pen – and Keyword Vocabulary from two years ago.
The core/fringe distinction is now so embedded in the world of augmentative communication that it is rare to see any new app appear on the market that doesn’t use the phrase “core vocabulary” somewhere in its marketing blurb – even if it isn’t actually making good use of the core! And as core vocabulary is, by definition, common across ages, activities, situations, and pathologies, it’s not surprising that many AAC software offerings look the same, particularly with regard to the words being encoded .