Open AccessAN EMPIRICAL STUDY OF THE NORMALITY AND INDEPENDENCE OF ERRORS OF MEASUREMENT IN TEST SCORES *
Author(s) -
Lord Frederic M.
Publication year - 1958
Publication title -
ets research bulletin series
Language(s) - English
Resource type - Journals
eISSN - 2333-8504
pISSN - 0424-6144
DOI - 10.1002/j.2333-8504.1958.tb00274.x
Subject(s) - normality , statistics , observational error , variance (accounting) , test (biology) , econometrics , independence (probability theory) , normality test , mathematics , standard error , psychology , statistical hypothesis testing , accounting , economics , paleontology , biology
An empirical study is described for determining whether in actual practice the errors of measurement in a test score (a) are distributed normally and (b) independently of the true score. Standard error formulas are given for making the necessary significance tests. The results show that the variance of the errors of measurement was significantly associated with true score in each of the four groups studied, and that the distribution of the errors of measurement was significantly skewed in three of these four groups.