Hand-scoring error rates in psychological testing

Despite the comprehensive treatment of test validity in most technical manuals, test authors appear to routinely assume that clients and professionals will score their instruments without error. Recently Allard and Faust challenged this assumption by suggesting that error rates "may not be rare or benign" and demonstrated that tests with more complex scoring procedures were associated with a greater number of scoring errors. This study investigated error rates that resulted from hand scoring seven psychometric tests commonly employed in psychological practice. Significant and serious error rates were identified for both psychologist and client scorers across all tests investigated. Scoring complexity was found to predict the base rate of scorer errors. The findings suggest that greater development in and attention to test-scoring procedures is required to restrict the likelihood of scorer error.