This book provides an introduction to test equating, scaling and linking, including those concepts and practical issues that are critical for developers and all other testing professionals. In addition to statistical procedures, successful equating, scaling and linking involves many aspects of testing, including procedures to develop tests, to administer and score tests and to interpret scores earned on tests. Test equating methods are used with many standardized tests in education and psychology to ensure that scores from multiple test forms can be used interchangeably. Test scaling is the process of developing score scales that are used when scores on standardized tests are reported. In test linking, scores from two or more tests are related to one another. Linking has received much recent attention, due largely to investigations of linking similarly named tests from different test publishers or tests constructed for different purposes. In recent years, researchers from the education, psychology and statistics communities have contributed to the rapidly growing statistical and psychometric methodologies used in test equating, scaling and linking. In addition to the literature covered in previous editions, this new edition presents coverage of significant recent research.

In order to assist researchers, advanced graduate students and testing professionals, examples are used frequently and conceptual issues are stressed. New material includes model determination in log-linear smoothing, in-depth presentation of chained linear and equipercentile equating, equating criteria, test scoring and a new section on scores for mixed-format tests. In the third edition, each chapter contains a reference list, rather than having a single reference list at the end of the volume

The themes of the third edition include:

* the purposes of equating, scaling and linking and their practical context

* data collection designs

* statistical methodology

* designing reasonable and useful equating, scaling, and linking studies

* importance of test development and quality control processes to equating

* equating error, and the underlying statistical assumptions for equating

Michael J. Kolen is a Professor of Educational Measurement at the University of Iowa. Robert L. Brennan is E. F. Lindquist Chair in Measurement and Testing and Director of the Center for Advanced Studies in Measurement and Assessment at the University of Iowa. Both authors are acknowledged experts on test equating, scaling and linking, they have authored numerous publications on these subjects, consult regularly on these topics and they have taught many workshops and courses on equating. Both authors have been President of the National Council on Measurement in Education (NCME), have received an NCME award for Career Contributions to Educational Measurement and have received an NCME award for Outstanding Technical Contributions to Educational Measurement following publication of the first edition of this book. Professor Brennan authored Generalizability Theory published by Springer-Verlag.