Quantitative Division

My research has focused primarily on improving large scale educational assessments, specifically on issues of test reliability and validity.

I am a practitioner turned professor. I spent nine productive years in the testing industry before moving to academia in 2001. From 1992 to 1999, I was a Research Scientist at Educational Testing Service (ETS) in Princeton, New Jersey. From January 1999 to August 2001, I held the position of Senior Psychometrician and Director of Computerized Testing Technological Research at the prestigious National Board of Medical Examiners (NBME) in Philadelphia.

Today, one main challenge in assessment is to develop theories and methods for the wide-ranging implementation of computerized assessment. Most recently, my work has been concentrated on developing item selection methods for computerized adaptive testing (CAT) including alpha-stratification (i.e., Chang, Qian, & Ying 2001), global information (Chang, 1996), and constraint-weighted information (Cheng and Chang, 2009). I tackle research problems that emerge from real world applications. For instance, one problem was to identify a design flaw in the computerized testing system that failed to generate reliable scores for thousands of GRE and GMAT test takers from 2000 to 2002. Along with Zhiliang Ying at Columbia University, I proposed a theory, and presented both analytical and empirical evidence, to support our hypothesis (Chang & Ying 2007). This research effort has been recognized by the 2008 Annual Tech Award of National Council on Measurement in Education (NCME).

Representative Publications:

• Chang, H., & Ying, Z. (2009). Nonlinear sequential designs for logistic item response theory models with applications to computerized adaptive tests. The Annals of Statistics, Vol 37, No. 3, 1466-1488.
• Cheng, Y., & Chang. H. (2009). The maximum priority index method for severely constrained item selection in computerized adaptive testing. British Journal of Mathematical and Statistical Psychology, 62, 369-383.
• Cheng, Y., Chang, H., Douglas, J., & Guo, F. (2009). Constraint-weighted a-startification for computerized adaptive testing with nonstatitical constraints -- balancing measurement efficiency and exposure control. Educational and Psychological Measurement, 69, 35-49.
• McGlohen, M. & Chang, H. (2008). Combining computer adaptive testing technology with cognitively diagnostic assessment, Behavior Research Methods, 40 (3), 808-821.
• Chang, H., & Ying, Z. (2008). To weight or not to weight? Balancing influence of initial items in adaptive testing. Psychometrika, 73 (3), 441-450.

Classes Recently Taught:

• Classical Test Theory, Item Response Theory, Measurement & Evaluation, Measurement & Test Development Lab, Computerized Testing
• Learning Theory
• Introduction to Statistics, Correlation & Regression, Multivariate Methods, Hierachical Linear Models