Observer reliability as a function of circumstances of assessment.

THREE FACTORS CHARACTERISTIC OF EXPERIMENTAL SETTINGS WERE HYPOTHESIZED TO INFLATE ARTIFACTUALLY THE RELIABILITY OF OBSERVATIONAL RECORDINGS: (a) knowledge by observers of when and by whom their reliability is being assessed, (b) the absence of the experimenter or a monitor to prevent cheating, and (c) computation of reliability within- (versus between-) observer group. Three groups of four observers used a standard nine-category observational code for disruptive behavior in recording from videotapes of a classroom for 22 days. Analyses revealed considerable increases in average occurrence reliability as a function of the main effects of each of the experimental factors. The specific increases in reliability associated with each of the 12 combinations of the experimental factors are presented for each category of behavior. The possible role of observer-training procedures and behavioral definitions as determiners of nonartifactual reliability is discussed.