Assessing the Psychometric Properties of Alternative Items for Certification

Alternative items were added as scored items to the National Certification Examination for Nurse Anesthetists (NCE) in 2010. A common concern related to the new items has been their measurement attributes. This study was undertaken to evaluate the psychometric impact of adding these items to the examination. Candidates had a significantly higher ability estimate in alternative items than in multiple choice questions and 6.7 percent of test candidates performed significantly differently in alternative item formats. The ability estimates of multiple choice questions correlated at r = .58. The alternative items took significantly longer time to answer than standard multiple choice questions and discriminated to a higher degree than MCQs. The alternative items exhibited unidimensionality to the same degree as MCQs and the BIC confirmed the Rasch model as acceptable for scoring. The new item types were found to have acceptable attributes for inclusion in the certification program.