The study examined the effects of educational treatment on 62 children (5 to 16-years-old) in a care unit for ambulant, trainable, low-moderate, and severely mentally handicapped children. Educational programing was provided in four areas: gross motor, motor perceptual, language, and social training. Results showed that the experimental children made significantly greater progress in two of the three areas of development (mental age and social age) than did their controls over the program's 2 years. In the third area, language, gains in favor of the experimental groups in expressive language did not reach significance level, and, unexpectedly, the controls showed greater actual, though again non-significant gains in receptive language. (SBH)