In Ramsay-curve item response theory (RC-IRT), the latent variable distribution is estimated simultaneously with the item parameters. In extant Monte Carlo evaluations of RC-IRT, the item response function (IRF) used to fit the data is the same one used to generate the data. The present simulation study examines RC-IRT when the IRF is imperfectly…

Differential item functioning (DIF) occurs when items on a test or questionnaire have different measurement properties for one group of people versus another, irrespective of group-mean differences on the construct. Methods for testing DIF require matching members of different groups on an estimate of the construct. Preferably, the estimate is…

In the bookmark standard-setting procedure, judges place "bookmarks" in a reordered test booklet containing items presented in order of increasing difficulty. Traditionally, the bookmark difficulty location (BDL) is on the trait continuum where, for dichotomous items, there is a two-thirds probability of a correct response and, for a score of "k"…