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The Use of Orthogonal Contrasts in the Interpretation of Records of Verbal Behaviors of Classroom Teachers

Medley, Donald M
Publication Year:
Report Number:
ETS Research Memorandum
Document Type:
Page Count:
Subject/Key Words:
Classroom Observation Techniques, Classroom Research, Teacher Behavior, Teacher Effectiveness, Test Construction


This paper describes and presents a progress report on the OSCAR technique for measuring objective, quantitative descriptions of specific teacher behaviors by relatively unsophisticated classroom observers. Possible uses for this technique include both evaluation of teacher-pupil interactions and teacher training. A specific version of this, OSCAR 4V, concerned with recording teacher verbal behaviors only, is described, and a technique for converting the data recordable by the observers to data interpretable by the teachers - orthogonal contrasts - is also described. An illustration of both techniques is presented, based on data collected in the classrooms of 70 secondary intern teachers. Several reasons are given why this statistical technique works better for this particular test (OSCAR) than a factor analysis with an appropriate rotation.

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