Semantic compaction

Semantic compaction also known as iconic encoding or Minspeak, is an Augmentative and alternative communication technique in which sequences of icons (pictorial symbols) are combined in order a word or a phrase from an AAC device in order increase a person's rate of speech.^[1][2][3]

Conceptual basis

Linguist Bruce Baker was the first to develop this idea of sequencing picture symbols as an encoding system and patented this concept under the name Minspeak.^[4] Symbol sets that use iconic encoding are different from other sets in that there is not a one-to-one correspondence between a symbol and its meaning.^[5] As the symbols typically contain a variety of details, each symbol may be associated with multiple meanings.^[5] For example, a Minspeak symbol depicting a dog holding a newspaper can also represent the concepts dog, pet and bring/get, depending on the other symbols with which it is combined.^[5] Minspeak provides a means of coding language whereby specific combinations of symbols generate specific messages.^[5] In order to facilitate vocabulary recall, this system uses a rule-based system of ordering the pictures.^[5] For example, all colour words begin with the same Rainbow symbol, followed by a symbol indicating that specific colour.^[5] Minspeak concepts can also be used with pre-programmed vocabulary sets called Minspeak Application Programs (MAPs) and later these messages and symbol combinations may be determined by the AAC user him/herself if desired.^[5] MAPs are used as initial starter vocabulary sets until this later customization is done by the user.^[5] Nonspeaking individuals using Minspeak software must be able to logically sequence encoded picture sequences together.^[4]

Words Strategy is a Minspeak software program that uses a more advanced form of iconic encoding, designed for the adolescent or adult AAC user who is able to combine words into more complex sentence sequences using picture-grammar symbol sequences.^[5] This application allows for the generation of more than 2,500 words using this sequencing format.^[5]

Unity is another Minspeak software program that was designed to teach preschool children language concepts using single picture symbols.^[5] Initially, a core vocabulary of a symbol set is learned until symbol sequences are gradually added using this same picture symbol set.^[5] Unity has three levels which proceed to adolescents and young adults. This symbol set uses categorization and association to create symbol sequences. For example, "Cat" is represented by the sequence "Zebra + Dog + Bed" whereby "Zebra" signifies a sequence representing an animal, "Dog" signifies the subcategory pets, and "Bed" is the symbol associated with the word "cat" since cats sleep in beds.^[5] Part of Speech Markers may also be used in this symbol set, such that the concept "Hot" is generated by a sequence containing a symbol and the Part of Speech Marker "Adjective".^[5]

Learnability

Several studies of typically developing children between 2–5 years have shown that semantic compaction strategies are challenging for young children to learn.^[6][7][8] Four and five year old children were less accurate in finding vocabulary iconic encoding strategies than other methods of organizing vocabulary such as by category, or on a visual scene.^[6] They proposed several possible reasons for the children's difficulties "including a possible lack of understanding of the semantic associations of the icons; a lack of conceptual knowledge required to understand multiple associations; and limited knowledge of parts of speech (several icon combinations required the use of a speech marker for adjective, preposition, and interjection)."^[1] A follow up study found that icon prediction, in which the options available for selection are highlighted, did not help children to locate vocabulary more accurately, but there was some evidence that the use of icon prediction may facilitate generalization of semantic compaction strategies to new vocabulary items.^[1]

References

1. ^ ^{a b c} Drager, K., ‌Light, J., (2010) A Comparison of the Performance of 5-year-old Children with Typical Development using Iconic Encoding in AAC Systems with and without Icon Prediction on a Fixed Display Augmentative and Alternative Communication 26:1, 12-20
2. ^ Beukelman, D. and Mirenda, P. (2005). Augmentative and Alternative Communication: Supporting Children and Adults with Complex Communication Needs. (3rd edition). Baltimore: Brookes.
3. ^ Minspeak: We give you language. Semantic Compaction Systems. 20 April 2010.
4. ^ ^{a b} Baker, B. (1986). Using Images to generate speech. Byte. 160-168.
5. ^ ^{a b c d e f g h i j k l m n} Glennen, Sharon L. and Decoste, Denise C. (1997). The Handbook of Augmentative and Alternative Communication. Singular Publishing Group, Inc.: San Diego, CA. pp. 122-23
6. ^ ^{a b} Light, J., ‌Drager, K., ‌McCarthy, J., ‌Mellott, S., ‌Millar, D., ‌Parrish, C., ‌Parsons, A., ‌Rhoads, S., ‌Ward, M., ‌Welliver, M. ‌(2004). Performance of typically developing four- and five-year-old children with AAC systems using different language organization techniques. Augmentative and Alternative Communication, 20, 63–88
7. ^ Drager, K. D. R., ‌Light, J. C., ‌Curran Speltz, J., ‌Fallon, K. A., ‌Jeffries, L. Z. ‌(2003). The performance of typically developing 2 ½-year-olds on dynamic display AAC technologies with different system layouts and language organizations. Journal of Speech Language Hearing Research, 46, 298–312.
8. ^ Drager, K., ‌Light, J., ‌Carlson, R., ‌D'Silva, K., ‌Larsson, B., ‌Pitkin, L., ‌Stopper, G. ‌(2004). Learning of dynamic display AAC technologies by typically developing 3-year-olds: Effect of different layouts and menu approaches. Journal of Speech Language Hearing Research, 47, 1133–1148.