Insight Psychometrics Technical Manual - Canadian Test Centre

Figure 25: Standard errors of measurement for CAT·4 standard scores bylevelLevelCAT·4ReadingCAT·4WritingConventionsCAT·4Mathematics10 17.4 24.611 15.4 16.012 15.4 25.5 12.313 14.1 25.5 12.314 12.1 18.9 9.915 12.1 19.9 10.516 12.1 21.8 9.917 12.1 20.8 9.918 12.7 18.0 9.919 12.1 18.9 10.520 21.8This information is used for reporting purposes as follows:1. Upper and lower confidence bounds for the CAT·4 score are based onthe normal distribution with the standard errors of measurement asgiven in Figure 25.2. The predicted CAT·4 score is calculated from Age in years and theInsight subtests using the regression formulas given in the top part ofFigure 24.3. Upper and lower confidence bounds for that prediction (assuming thatthe student received an actual CAT·4 score which is the same score aspredicted when s/he wrote the same level of CAT·4) based again on thestandard error of measurement given in Figure 25.4. The percentile of the discrepancy between CAT·4 and the prediction,based on normal distribution and the standard error of regressions asgiven in the bottom part of Figure 24.5. The significance (.05) of the residual deviation of the CAT·4 predictionfrom the actual is tested, based on percentile discrepancy.24