Construct equivalence of multiple-choice and constructed-response items: A random effects synthesis of correlations

A thorough search of the literature was conducted to locate empirical studies investigating the trait or construct equivalence of multiple-choice (MC) and conslructed-response (CR) items. Of the 67 studies identified, 29 studies included 56 correlations between items in both formats. These 56 correlations were corrected for attenuation and synthesized to establish evidence for a common estimate of correlation (true-score correlations). The 56 disattenuated correlations were highly heterogeneous. A search for moderators to explain this variation uncovered the role of the design characteristics of test items used in the studies. When items are constructed in both formats using the same stem (stem equivalent), the mean correlation between the two formats approaches unity and is significantly higher than when using non-stem-equivalent items (particularly when using essay-type items). Construct equivalence, in part, appears to be a function of the item design method or the item writer's intent.