The Reliability, Validity, and Utility of Three Handwriting Measurement Procedures

This study investigated the reliability, validity, and utility of the following three measures of letter-formation quality: (a) a holistic rating system, in which examiners rated letters on a five-point Likert-type scale; (h) a holistic rating system with model letters, in which examiners used model letters that exemplified specific criterion scores to rate letters; and (c) a correct/incorrect procedure, in which examiners used transparent overlays and standard verbal criteria to score letters. Intrarater and interrater reliability coefficients revealed that the two holistic scoring procedures were unreliable, whereas scores obtained by examiners who used the correct/incorrect procedure were consistent over time and across examiners. Although all three of the target measures were sensitive to differences between individual letters, only the scores from the two holistic procedures were associated with other indices of handwriting performance. Furthermore, for each of the target measures, variability in scores was, for the most part, not attributable to the level of experience or sex of the respondents. Findings are discussed with respect to criteria for validating an assessment instrument.