The rationale of the Observation Schedule and Record (OScAR) is described, and research is reported to show the extent to which the form fulfills its purposes. In order to provide objective, reliable, and valid information about the teaching process, this classroom observation schedule is used to record the frequency of occurrence of 42 teacher behaviors only. The scores for OScAR are based on 41 contrast keys showing the relative frequencies among sets of the 42 observed behaviors. Eighteen keys are based on contrasts among statements and non-substantive interchanges, 3 keys on entries to substantive interchanges, 5 keys on exits from substantive interchanges, and 15 keys on interaction entries and exits. Research on the schedule is based on a study of 70 teacher interns in secondary schools, with four observations of each teacher. Simultaneously other observers recorded the same situation using the Flanders' Interaction Analysis Technique. Analysis of variance was used to estimate score reliabilities and factor analysis of both rating forms together was used for score interpretation. Scores were also related to subscores on the National Teacher Examination. (CTM)