Terry Ackerman (Professor, ERM)

My research has focused on practical applications of item response theory (IRT). These include computerized adaptive testing, test construction, equating, differential item/test functioning and ability estimation. More recently I have been concentrating on extending the concepts of unidimensional IRT to the multidimensional case. Whether it is intended or not many standardized tests measure multiple skills. If this is the case, then such things has score interpretation, differential item/test functioning and the degree to which alternate forms are truly parallel need to be examined. To examine items and tests from a multidimensional perspective I have developed a series of graphical techniques that help the testing practitioner better understand the various composites of skills their items and tests are measuring. One of my goals is to help testing practitioners realize that testing should be a cyclical process. After a test is administered and the student performance is analyzed at both the item and test level, this information needs to be recycled back into the test development process to cross validate and improve the assessment. There has to be a working dialogue established between the item writers, the test editors and the psychometricians.

 I have worked on several large-scale testing programs including the ACT Assessment, the Law School Admissions Test and the Illinois statewide test, the IGAP. I have also been involved in setting up a computerized testing system at 29 Palms Marine Base in California and helped write a computerized dermatology test for the Medical College of Wisconsin.

 Dr. Terry A. Ackerman (Ph.D., University of Wisconsin-Milwaukee, 1984) joined the UNCG faculty in 1999. Prior to joining the ERM Department, Dr. Ackerman was an Associate Professor at the University of Illinois in Champaign-Urbana. He was an Associate Chair of the Department of Educational Psychology and taught courses in measurement and statistics. He also had zero-time appointments with the Department of Statistics and the Department of Psychology. Dr. Ackerman also served on the Illinois State Board of Education’s Technical Advisory Committee. Previously he was an Assistant Director/Psychometrician at ACT, Inc in Iowa City, Iowa.

Selected Publications

 Ackerman, T. A. (1989). Unidimensional IRT calibration of compensatory and non-compensatory multidimensional items. Applied Psychological Measurement, 13, (2), 113-127.

Ackerman, T. A. (1992). A didactic explanation of item bias, item impact, and item validity from a multidimensional perspective, Journal of Educational Measurement, 29 (1) 67-91.

Ackerman, T.A. & Evans, J. A. (1994). The influence of conditioning scores in performing DIF analyses. Applied Psychological Measurement, 18 (4) 329-342.

Ackerman, T. A. (1996). Graphical representation of multidimensional item response theory analyses. Applied Psychological Measurement, 20, (4) 311-329.

Ackerman, T. A. , Evans, J. A., Park, K., Tamassia, C. & Turner, R. (1999) Computer assessment using visual stimuli: A test of dermatological skin disorders. In F. Drasgow &

J. B. Olson-Buchanan (Eds.), Innovations in computerized assessment. Mahwah, NJ: Lawrence Erlbaum Associates, Publishers.