Intrarater and Interrater Objectivity of the Erhardt Developmental Prehension Assessment among Trained and Untrained Examiners

Abstract

Seven trained and eight untrained examiners rated the videotaped performance of one child with the Erhardt Developmental Prehension Assessment to determine intrarater and interrater objectivity. Objectivity is one component of reliability. Reliability studies reflect errors because of subject performance changes and rater inconsistencies in applying scoring criteria. Objectivity, through the use of videotaped performances, investigates those errors in assessments caused by the inconsistency of applying scoring criteria. Findings demonstrated high levels of intrarater objectivity and moderate to high levels of interrater objectivity for trained examiners. Training led to significantly increased correlation coefficients for interrater tests. Results of the study are discussed in relation to possible sources of instability of scores, the use of the assessment in the clinic, and directions future research could take in further development of this instrument.