Investigation of 360-degree instrumentation effects: application of the Rasch rating scale model.

Performance appraisals have been frequently investigated for inaccuracies attributable to raters. In addition to rater contributions, problems in measurement can arise from properties of instrumentation. If administered items do not parallel the full range of employee performance, a restriction of range can occur. Here employees are rated similarly (no distinction made) not because of rater error, but because of an instrument floor or ceiling effect. A RASCH measurement procedure was applied to a 360-degree dataset in order to uncover potential instrumentation effects. A similar magnitude ceiling effect was found across rater categories. It is recommended that performance appraisal practitioners consider including items of greater difficulty in their criterion measures.