A training manual is presented to insure reliable use of the Assessments of Performance in Teaching (APT) observational evaluation instrument. The 24-hour training program's major instructional method requires round-table discussions of observations. Videotaped teacher demonstrations are required for practice and criterion assessments. The instrument was derived from state and national teacher evaluation forms and a survey of South Carolina educators. The classroom observational assessment is meant to measure minimal competence to apply fundamental teaching skills regardless of subject area, grade level or context. Five Performance Dimensions presented in the observation instrument are measured in a composite of three observer ratings. Notes on objectives and student differences are described with the instrument procedures, nature of the observations and observer standards. The training manual describes training program preparations, session structure and a supplement for trainers of field coordinators. Appendices include materials for use in training observation and conference procedures. (CM)