The adequacy of equipercentile, linear, one-parameter (Rasch), and three-parameter logistic item-response theory procedures for equating 12 forms of five tests of general educational development were compared. Results indicated the equating method adequacy depends on a variety of factors such as test characteristics, equating design, and sample…

Methods and results relevant to the introduction of item characteristic curve (ICC) models into classroom achievement testing are provided. The overall objective was to compare several common ICC models for item calibration and test equating in a classroom examination system. Parameters for the one-, two- and three-parameter logistic ICC models…

Data from the verbal portion of the College Entrance Examination Board Scholastic Aptitude Tests were used in an experimental test of the accuracy of equating for a variety of models in three categories: linear equating, equipercentile equating, and item characteristic curve equating. The models were tested for both mean squared error and bias.…

By means of computer simulation of test responses, the reliability of item analysis data and the accuracy of equating were examined for hypothetical samples of 250, 500, 1000, and 2000 subjects for two tests with 20 equating items plus 60 additional items on the same scale. Birnbaum's three-parameter logistic model was used for the simulation. The…

A general process for testing the feasibility of applying alternative mathematical or statistical models to the solution of a practical problem is presented and flowcharted. The system is used to develop a plan to compare models for test equating. The five alternative models to be considered for equating are: (1) anchor test equating using…

Combinations of five methods of equating test forms and two methods of selecting samples of students for equating were compared for accuracy. The two sampling methods were representative sampling from the population and matching samples on the anchor test score. The equating methods were: (1) the Tucker method; (2) the Levine method; (3) the…

This study investigated the adequacy of the Rasch model in equating existing standardized tests with groups of examinees not widely separated in ability. With the exception of one test pair and one grade level, the Rasch model using the anchor test procedure provided a reasonably satisfactory means of equating. (Author/CTM)

Six methods of equating Test of English as a Foreign Language (TOEFL) test scores for samples consisting of the usual groups of examinees and groups controlled for native language representation were evaluated in terms of scale stability. The equating methods included three item response theory (IRT) variants (fixed b's scaling, a one-parameter…

This paper examines how various equating methods are affected by: (1) sampling error; (2) sample characteristics; and (3) characteristics of anchor test items. It reviews empirical studies that investigated the invariance of equating transformations, and it discusses empirical and simulation studies that focus on how the properties of anchor tests…

This partially annotated bibliography of journal articles, dissertations, convention papers, research reports, and a few books and unpublished manuscripts provides a comprehensive coverage of work on latent trait theory and practice. Documents are arranged alphabetically by author. The period covered ranges from the early 1950's to the present.…

Development of The Assessment of Basic Competencies (ABC), a test battery based on the three-parameter logistic model, is described. Eleven dimensions of intellectual growth are measured, from the pre-kindergarten level through ninth grade. An educationally relevant skill domain is represented by each test. Unique properties of the test, based on…