Multistage testing among several adaptive testing types has been more frequently applied into
 practice because it can accurately and efficiently estimate abilities with relatively short tests. However,
 it has been also criticized due to its low level of adaptability. To address this issue, the intersectional
 routing method was proposed and its effectiveness has been partly confirmed. This study aims to
 explore the effectiveness of the intersectional routing method with mixed-format MST by applying the
 bi-factor MIRT model, and the UIRT model, extending previous researches. Based upon the results of
 this study, when the module length was short (8 items), and the correlation between sections was
 high (0.9), the accuracy of ability estimates using the intersectional routing was higher than the
 typical multistage testing design regardless of the IRT model. The application of the intersectional
 routing technique decreased the differences of ability estimate accuracy in accordance with panel
 designs. Considering the high inter-correlation values between sections in actual tests (ranging from 0.6
 to 0.9), the application of the intersectional routing method into multistage testing could be a choice
 for broadening options in test designs and obtaining more accurate ability estimates. The results also
 indicate the necessity of selecting an appropriate IRT model based on test characteristics in
 multidimensional adaptive testing situations.
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