Comparing conditional standard error of measurement among non-linear raw to scale scores methods

In order to the better interpreting and comparing scores in test batteries the raw scores in each test are converted to a common scale that called scale score. There are different Linear and nonlinear methods to convert raw scores to scale scores. Conventional methods of non-linear converting raw scores to scale scores are normalization and Arcsine methods. In This study that aimed to compare the standard error of measurement in non-linear converting methods we used 10000 random simulated sample data and 10000 random real sample data from Iran university entrance exam applicants.in order to compare converting methods conditional standard error of measurement that called CSEM, frequency charts and statistical indexes like moments was used. The results showed that both methods have different features. Although scores in both methods have high reliability and accuracy but Arcsine method reducing score error undulation for different score levels, also the mean of standard error of measurement for Arcsine scale scores was less than normalized scale scores.