An Investigation of the Accuracy of Alternative Methods of True Score Estimation in High-Stakes Mixed-Format Examinations


  • Don A. Klinger
  • W. Todd Rogers



Increasingly, high-stakes large-scale examinations are used to make important decisions about student achievement. Consequently, it is equally important that scores obtained from these examinations are accurate. This study compares the estimation accuracy of procedures based on classical test score theory (CTST) and item response theory (Generalized Partial Credit model, GPCM) for examinations consisting of multiple-choice and extended-response items. Using the British Columbia Scholarship Examination program, the accuracy of the two procedures was compared when the scholarship portions of the examinations were removed. For the subset of examinations investigated, the results indicate that removing these scholarship portions led to an error rate of approximately 10% with approximately seven out of 10 errors resulting in the denial of scholarships. The results were similar for both the CTST and the GPCM, indicating that for mixed-format examinations the two procedures produce randomly equivalent results. Implications for policy and future research are discussed.