Public awareness about individuals with mental retardation has increased in the past years. Comprising 4.6% of the population in developed countries including the Philippines, these individuals gained considerable acceptance from the public and have found their place in special schools in the hope to live a productive life.
In line with this, special educators sought for ways in order to provide the best learning possible for these individuals. Various movements have emerged and presented new ways of teaching considering the special needs of these individuals. These trends remain dynamic, presenting new findings and recommendations as results of research and study.
There has been relatively little research on the vocabulary abilities of children with mental retardation. Some researches, like that of Ezell & Goldstein (1991), indicate that children with mental retardation tend to be more concrete in their understanding of words. This tendency to be more concrete may be the result of delays in development of semantic abilities (Rosenberg, 1982) and being lag behind in their development of organizing strategies (Stephens, 1972)
In respect with the above-mentioned ideas, studying the effect of using contextualized visual aids to increase the vocabulary of children with mental retardation is a significant and meaningful investigation. It is with an utmost conviction to the idea that in order to effectively teach these children, teaching approach must be integrated- multisensory and culturally/contextually-relevant. Multisensory in a sense that the more senses being used, the more learning takes place. On the other hand, to be culturally/contextually-relevant simply means that learning will be more effective when differences in the learner’s linguistic, cultural and social background are also taken into account (13th Principle: American Psychological Association’s 14 Learner-Centered Principles, in Corpuz and Lucas, 2007).
Mental retardation is defined by the World Health Organization as a condition of incomplete or halted development of the mind, which is characterized by impairment of skills as manifested during developmental period that contributes to the overall level of intelligence.
Most children with mental retardation have problems with language and communication (Long & Long, 1994). In fact, language and speech disorders have been found to be the most frequent secondary disability among children with mental retardation (Epstein, Polloway, Patton, & Foley, 1989). Deficits in language and communication have been found to "constitute major impediments to the social, emotional, and vocational adjustment of retarded citizens" (Swetlik & Brown, 1977).
Research about vocabulary abilities of children with mental retardation is said to be limited as compared to other language development concerns. Children with mental retardation have been found to lag behind in their development of organizing strategies (Stephens, 1972) and to use more concrete concepts (Mac Millan. 1982), suggesting that children with mental retardation have some difficulty developing and using semantic concepts.
On the other hand some studies have found that an area of strength for children with mental retardation is that of vocabulary skills. In a study of the comprehension of syntax and vocabulary conducted by Chapman, Schwartz, and Kay Raining-Bird (1991), the authors found that their subjects with mental retardation performed significantly better on the vocabulary comprehension task than on tests of syntactic skills.
Theories Underlying the Use of Visual Aids
Over the years, educators agree that the use of visual aids enhances learning both to children with or without special needs (with the exception for some cases i.e. visually-impaired children). Jerome Bruner initially supported this when he proposed that learners can learn through Iconic mode or through the use of pictures and images. According to Machado (2007), visuals and images (pictorial representations) used during instructions almost always improve students’ attention, listening and comprehension and reduces recall errors.