Most people are not comfortable with the numerical aspect of tests, and well they should be. As we know, tis better to accept dubious conclusions than to believe sensible ones. Another reason why we distain numbers so much is that this nation is, on average, a nation of dyscalculics. As indicated in Table 5.1, the reliability coefficients for the scales are sometimes greater than those for the individual subtests. Somehow, the SEM provides an estimate of the amount of error in an individual's score.
Confidence intervals provide another means of expressing the imprecision of scores.
They also assist in avoiding due process hearings by providing a range of scores in which the true score is likely to fall. The reporting of confidence intervals also serves as a reminder that the observed score contains some amount of measurement error. Remember, you are the expert. You can discover the person's TRUE score and thus their TRUE ability. This method is more technically imprecise Confidence intervals developed with this method are much less interpretable in the manner discussed poorly above.