This technical manual describes "The Arc's Self Determination Scale," a student self-report measure of self-determination designed for use by adolescents with disabilities, particularly students with mild mental retardation and learning disabilities. The test was designed to be a tool to enable students to become more self-determined by enabling them to evaluate their beliefs about themselves and their self-determination, work collaboratively with educators and others to identify individual areas of strength and limitations related to self-determination goals and objectives, and self-assess progress in self-determination over time. The scale is subdivided into four conceptually distinct subscales: (1) self and family care, which includes items that measure basic daily living activities, specifically routine personal care and family-oriented activities; (2) management, which includes items measuring the degree to which students handle their interactions with the environment; (3) recreation activity, which contains items that indicate the youth's recreational and leisure time activities; and (4) social and vocational activities, which contain items that measure the adolescent's social involvement and vocational goals, plans, and activities. The manual describes the theoretical basis for the scale, scale construction and development, administration, scoring and interpretation, test norms, and test reliability and validity. A copy of the adolescent version of the test is included. (Contains 106 references.) (CR)