Computerized adaptative testing (CAT) still have a host of advantages but also some drawbacks. For example, as Wainer (2000, p. xxiii) stated, high stake tests like exams are not good candidates for computerized tests. Also, as the number of items is limited in CAT, the process of detecting biased (DIF) items is vital. This paper suggests a DIF method specially aimed at identifying biased items in a CAT context. A person-fit index for adaptive testing will also be proposed.