Symbols are verbal or visual representations of concepts and ideas. Aided AAC methods use visual symbols in the form of graphics such as a picture or object.
When choosing a symbol system, the iconicity of the symbols needs to be considered. Iconicity is the amount that a visual symbol relates to its referent. In other words, it’s how much the symbol resembles the intended message. There are 3 levels of iconicity as cited in Bloomberg et al., 1990; Fuller & Lloyd, 1991:
Transparent: These symbols visually resemble their referents and are easily guessable (McClure & Rush, 2007). For example, a picture of a “cup” represents a “cup.”
Translucent : Additional information is needed for these types of symbols to be guessable (McClure & Rush, 2007). For example, a picture of a “cup” represents a “drink.”
Opaque: The symbols do not visually resemble their referents, and are not obvious, but often abstract (McClure & Rush, 2007). For example, a picture of a “cup” represents a “snack.”
Here is a list of aided symbol systems that have been traditionally listed in this hierarchical order from most easily guessable to more abstract. However, it is important to note that when determining which type of symbol system to use as cited in Brown, 1977, “iconicity is culture bound, time bound, and experience bound” (McClure & Rush, 2007).
1. Objects 2. Parts of objects 3. Colored photos 4. Black & white photos
5. Miniatures of objects 6. Colored pictures 7. Line drawings 8. Written words
*Some research suggests as cited in Schlosser & Sigafoos, 2002, “understanding is not the result of the symbol’s resemblance to its referent; rather, occurs because people have learned to read or recognize symbols” (McClure & Rush, 2007). Therefore, a variety of symbol systems should be trialed with the person with complex communication needs in order to determine which symbols are most easily understood for that specific individual.