To meet the requirements of the No Child Left Behind Act, school districts and states must compile summary reports of the levels of student achievement in reading and mathematics. The levels are to be described in broad categories: "basic and below," "proficient," or "advanced." Educational units are given considerable latitude in defining the…

The binomial error model includes form-to-form difficulty differences as error variance and leads to Ruder-Richardson formula 21 as an estimate of reliability. If the form-to-form component is removed from the estimate of error variance, the binomial model leads to KR 20 as the reliability estimate. (Author/BW)

Researchers sometimes need a statistical test of the hypothesis that two values of Cronbach's alpha reliability coefficient are equal. The situation may involve scores from two different measures administered to independent random samples or from the same measure administered to random samples from two different populations. Feldt derived a test…

The recommendation that the reliability of multiple-choice tests will be enhanced if the distribution of item difficulties is concentrated at approximately 0.50 is reinforced and extended in this article by viewing the 0/1 item scoring as a dichotomization of an underlying normally distributed ability score. (SLD)