Evaluation of the 1974-77 INREAL (INclass REActive Language) demonstration model project, initially serving 518 children (aged 3-5 years), focused on the Colorado program's objectives of increasing language handicapped and bilingual (Spanish) children's language development significantly and preventing later language-related learning problems in mild-to-moderate language handicapped children. Project goals were to improve the language and related learning skills of the children by a naturalistic, non-stigmatizing method using inclass service delivery, thus redefining the traditional role of the speech-language pathologist. A 1976-77 experimental study of matched INREAL and control groups measured language development and indicated that INREAL intervention effected highly significant language improvement. A longitudinal experimental study gathered data for three years (1977-80) after the INREAL program had ended and revealed that use of the INREAL method at preschool and kindergarten levels resulted in the need for substantially fewer follow-up remedial services (remedial reading, speech-language pathology and learning disabilities) and fewer retention-in-grade placements. A cost effectiveness study showed a per pupil saving on follow-up special services of $1,283.76 and a bilingual pupil saving of $3,073.16 for the three years studied. Per pupil instructional cost ($175) of INREAL treatment was absorbed within one year after treatment ended. (NEC)