Categorizing Teacher Behavior, developed to measure acquisition of concepts portrayed in the Concepts and Patterns in Teacher-Pupil Interaction film series, measures the ability to identify and categorize instances of the specificed concepts as they are portrayed in reasonably complex filmed classroom interactions. The film series itself is based upon three pairs of concepts referring to teacher behavior in an interactive setting. These pairs of concepts are: probing and informing, approving and disapproving, productive and reproductive questioning. The test consists of 30 classroom episodes, each less than one minute in length, selected from "out-takes" from the films in the series (that is, from footage not included in the instructional films themselves. In two studies using graduate educational psychology students, the test evidenced a high degree of reliability and validity. Directional predictions were confirmed using composite test scores and composite half-test scores in most instances. A discernible and significant gain in mean test performance can be accounted for by the instruction through the use of protocol films. An answer key and answer form are appended. (Author/MV)