The investigation compared the transparency of 11 different types of symbols with 40 nonspeaking mentally retarded subjects (ages 4-20). Analysis indicated a hierarchy of difficulty with actual objects the easiest and Blissymbols and written words the hardest to understand. Results have implications for selecting initial symbol systems for…

The investigation examined the transparency and recall of symbols representing three parts of speech (nouns, verbs, and descriptors) from three different graphic symbol systems (Blissymbols, Picture Communication System, and Picsyms) among adults with intellectual handicaps. Results suggested that Blissymbols were the least transparent and hardest…