Normative Data and Scoring
Percentile rank tables in Appendix A (Table 8 through 15) address each occupation area so the test administrator may plot the subject’s raw scores and convert them into a percentile score that can be recorded. This will enable the test administrator to conduct subject score comparisons with the normative population.
To utilize the percentile tables, identify the appropriate table (8 through 15) for the occupation area that best describes the subject. Locate the subject’s raw score or the average of 3 trials for each test battery under the corresponding heading (i.e., Right Hand, Left Hand) within the percentile box. Draw a line from that raw score across to the left or right outside edge of the box to where the percentile scores are located (1-99). This will give you the converted score, from raw scores to percentiles. Record this number on the score sheet. Note: If the subject’s preferred hand is the Left Hand, the Left Hand score should be looked up under the Right Hand column heading on these tables.
The Mean and Standard Deviations (S.D.) have also been provided at the bottom of each percentile table. Note: The Mean does not always represent 50th percentile, this may be attributed to sampling size and/or sampling error. The difference between the mean and 50th percentile do not seem to be significant. The Mean and S.D. can be used to plot the subject’s score on a bell-shaped curve and interpret using the standard scale or verbal scale. The instructions for using these scales appear in the next section.