Are Tests Comprising Both Multiple‐Choice and Free‐Response Items Necessarily Less Unidimensional Than Multiple‐Choice Tests?An Analysis of Two Tests

Abstract

We consider the relationship between the multiple‐choice and free‐response sections on the Computer Science and Chemistry tests of the College Board's Advanced Placement program. Restricted factor analysis shows that the free‐response sections measure the same underlying proficiency as the multiple‐choice sections for the most part. However, there is also a significant, if relatively small, amount of local dependence among the free‐response items that produces a small degree of multidimensionauty for each test