Feinstein, Zachary S.2011-11-032011-11-031995Feinstein, Zachary S. (1995). Effects of differing item parameters on closed-interval DIF statistics. Applied Psychological Measurement, 19, 131-142. doi:10.1177/014662169501900202doi:10.1177/014662169501900202https://hdl.handle.net/11299/117477The closed-interval signed area (CSA) and closed-interval unsigned area (CUA) statistics were studied by monte carlo simulation to detect differential item functioning when the reference and focal groups had different parameter distributions. When the pseudo-guessing parameter was varied, the CSA was better able to detectmoderate to large differences between the groups than the CUA. However, the effect of the pseudo-guessing parameter varied depending on item discriminations. Index terms: closed-interval measures, differential item functioning, item response theory, monte carlo simulation, signed area measures, unsigned area measures.enArticle