"Scaling" is the process of constructing a score scale that associates numbers or other ordered indicators with the performance of examinees. Scaling typically is conducted to aid users in interpreting test results. This module describes different types of raw scores and scale scores, illustrates how to incorporate various sources of…

A number of vertical scaling methodologies were examined in this article. Scaling variations included data collection design, scaling method, item response theory (IRT) scoring procedure, and proficiency estimation method. Vertical scales were developed for Grade 3 through Grade 8 for 4 content areas and 9 simulated datasets. A total of 11 scaling…

Linear and nonlinear methods for incorporating score precision information when the score scale is established for educational tests are compared. Examples illustrate the methods, which discourage overinterpretation of small score differences and enhance score interpretability by equalizing error variance along the score scale. Measurement error…

This paper reviews various procedures for constructing an interval for an individual's true score given the assumption that errors of measurement are distributed as binomial. This paper also presents two general interval estimation procedures (i.e., normal approximation and endpoints conversion methods) for an individual's true scale score;…

Describes four procedures previously developed for estimating conditional standard errors of measurement for scale scores and compares them in a simulation study. All four procedures appear viable. Recommends that test users select a procedure based on various factors such as the type of scale score of concern, test characteristics, assumptions…

Presents an Item Response Theory (IRT) method for estimating standard errors of measurement of scale scores for the situation in which scale scores are nonlinear transformations of number-correct scores. Also describes procedures for estimating the average conditional standard error of measurement for scale scores and the reliability of scale…

Developed a procedure for defining achievement levels on continuous scales using aspects of Guttman scaling (L. Guttman, 1950) and Item Response Theory. Using data from high school mathematics tests for about 6,000 students, found the new procedure to have higher reliability, higher classification consistency, and lower classification error than…

An instructional module is presented to promote a conceptual understanding of test form equating using traditional methods. Equating is distinguished from scaling. The equating methods described are: (1) mean; (2) linear; and (3) equipercentile. The module includes a self-test. (SLD)

A procedure is described for estimating the reliability and conditional standard errors of measurement of scale scores incorporating the discrete transformation of raw scores to scale scores. The method is illustrated using a strong true score model, and practical applications are described. (SLD)

This report presents an investigation by the American College Testing Program (ACT) of an alternative design for the National Assessment of Educational Progress (NAEP). The proposed design greatly simplifies the data collection and analysis procedures needed to produce assessment results and has the potential to produce results that are more…