A distinction is made between scores as measures of a construct and predictions of a criterion or outcome variable. The interpretation attached to predictions of criteria, such as job performance or college grade point average (GPA), differs from that attached to scores that are measures of a construct, such as reading proficiency or knowledge…

This manual contains technical information about the ACT® college readiness assessment. The principal purpose of this manual is to document the technical characteristics of the ACT in light of its intended purposes. ACT regularly conducts research as part of the ongoing formative evaluation of its programs. The research is intended to ensure that…

Professional standards for educational testing recommend that both the overall standard error of measurement and the conditional standard error of measurement (CSEM) be computed on the score scale used to report scores to examinees. Several methods have been developed to compute scale score CSEMs. This paper compares three methods, based on…

In this study, we investigated whether preequating results agree with equating results that are based on observed operational data (postequating) for a college placement program. Specifically, we examined the degree to which item response theory (IRT) true score preequating results agreed with those from IRT true score postequating and from…

This manual contains information about the American College Test (ACT) Plan® program. The principal focus of this manual is to document the Plan program's technical adequacy in light of its intended purposes. This manual supersedes the 2011 edition. The content of this manual responds to requirements of the testing industry as established in the…

Distinctions were made between three classes of statistical linkage: equivalence, concordance, and prediction. These distinctions were based on rational content considerations and empirical statistical relationships. A large database involving SAT I and ACT scores was used to determine which type of linkage was best suited for different scores and…

This study examined the usefulness of applying the Rasch rating scale model (D. Andrich, 1978) to high school grade data. ACT assessment test scores (English, Mathematics, Reading, and Science) were used as "common items" to adjust for different grading standards in individual high school courses both within and across schools. This…

This study examined the usefulness of applying the Rasch rating scale model (D. Andrich, 1978) to high school grades. ACT Assessment test scores (English, Mathematics, Reading, and Science Reasoning) were used as "common items" to adjust for different grading standards in individual high school courses both within and across schools.…

Correspondences between ACT[superscript TM] and SAT[superscript R] I scores are presented from a conceptual framework that distinguishes among three kinds of correspondences, namely, equating, scaling, and prediction. Construct similarity plays an important role in determining the nature and degree of correspondence that can be achieved. This…

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)

Effects of passage and item-scrambling on equipercentile and item-response theory equating were investigated using 2 scrambled versions of the American College Testing Program Assessment for approximately 25,000 examinees. Results indicate that using a base-form conversion table with a scrambled form affects the individual examinee level. (SLD)

This manual contains preliminary information, largely of a technical nature, about the enhanced American College Testing (ACT) Program introduced in October 1989. It focuses primarily on the tests of educational development, the component of the program that has been substantially revised. Although one-third of the ACT Interest Inventory Items has…