Differential Item Functioning on Antisocial Behavior Scale Items for Adolescents and Young Adults from Single-Parent and Two-Parent Families

We investigated measurement equivalence in two antisocial behavior scales (i.e., one scale for adolescents and a second scale for young adults) by examining differential item functioning (DIF) for respondents from single-parent (n = 109) and two-parent families (n = 447). Even though one item in the scale for adolescents and two items in the scale for young adults showed significant DIF, the two scales exhibited non-significant differential test functioning (DTF). Both uniform and nonuniform DIF were investigated and examples of each type were identified. Specifically, uniform DIF was exhibited in the adolescent scale whereas nonuniform DIF was shown in the young adult scale. Implications of DIF results for assessment of antisocial behavior, along with strengths and limitations of the study, are discussed

Detection of known items in adaptive testing with a statistical quality control method

Due to previous exposure of items in adaptive testing, items may become known to a substantial portion of examinees. A disclosed item is bound to show drift in the item parameter values. In this paper it is suggested to use a statistical quality control method for the detection of known items. The method is worked out in detail for the 1-PL and 3-PL models. Adaptive test data are used to re-estimate the item parameters, and these estimates are used in a test of parameter drift. The method is illustrated in a number of simulation studies, including a power study