Nonequivalent Groups-Linear Methods

Chapter 1 introduced the common-item nonequivalent groups design. For this design, two groups of examinees from different populations are each administered different test forms that have a set of items in common This design often is used when only one form of a test can be administered on a given test date. As discussed in Chapter 1, the set of common items should be as similar as possible to the full-length forms in both content and statistical characteristics.