Appendix

Mild mental retardation is roughly equivalent to what used to be referred to as the educational category of "educable". This group constitutes the largest segment of those with the disorder-about 85%. People with this level of mental retardation typically develop social and communication skills during the pre-school years(ages 0-5), have minimal impairment in sensori-motor areas, and often are not distinguishable from normal children until a later age. By their late teens, they can acquire academic skills up to approximately sixth grade level; during their adult years, they usually achieve social and vocational skills adequate for minimum self-support, but may need guidance and assistance when under unusual social or economic stress. At the present time, virtually all people with mild mental retardation can live successfully in the community, independently or in supervised apartments or group homes(unless there is an associated disorder that makes this impossible.)

Moderate mental retardation is roughly equivalent to what used to be referred to as the educational category of "trainable". This former term should not be used since it wrongly implies that people with moderate mental retardation cannot benefit from educational programs. This group constitutes 10% of the entire population of people with mental retardation. Those with this level of mental retardation can talk or learn to communicate during the pre-school years. They may profit from vocational training and, with moderate supervision, can take care of themselves. They can profit from training in social and occupational skills, but are unlikely to progress beyond the second grade level in academic subjects. They may learn to travel independently in familiar places. During adolescence, their difficulties in recognising social conventions may interfere with peer relationship. In their adult years, they may be able to contribute to their own support by performing unskilled or semi-skilled work under close supervision in sheltered workshops or in the competitive job market. They need supervision and guidance when under stress. They adapt well to life in the community, but usually in supervised group homes.

This group constitutes 3%-4% of people with mental retardation. During the pre-school period, they display poor motor development, they may learn to talk, and can be trained in elementary hygiene skills. They profit to only a limited extent from instruction in pre-academic subjects, such as familiarity with the alphabet and simple counting, but can master skills such as learning sight-reading of some "survival" words, such as "men" and"women" and "stop". In their adult years, they may be able to perform simple tasks under close supervision. Most adapt well to life in the community, in group homes or with their families, unless they have an associated handicap that requires specialised nursing or other care.