Although modern item response theory (IRT) methods of test construction and scoring have overcome ipsativity problems historically associated with multidimensional forced choice (MFC) formats, there has been little research on MFC differential item functioning (DIF) detection, where item refers to a block, or group, of statements presented for an examinee’s consideration. This research investigated DIF detection with three-alternative MFC items based on the Thurstonian IRT (TIRT) model, using omnibus Wald tests on loadings and thresholds. We examined constrained and free baseline model comparisons strategies with different types and magnitudes of DIF, latent trait correlations, sample sizes, and levels of impact in an extensive Monte Carlo study. Results indicated the free baseline strategy was highly effective in detecting DIF, with power approaching 1.0 in the large sample size and large magnitude of DIF conditions, and similar effectiveness in the impact and no-impact conditions. This research also included an empirical example to demonstrate the viability of the best performing method with real examinees and showed how a DIF and a DTF effect size measure can be used to assess the practical significance of MFC DIF findings.

尽管现代项目响应理论（IRT）的测试构造和评分方法克服了历来与多维强制选择（MFC）格式相关的渗透性问题，但对MFC差分项目功能（DIF）检测的研究很少，其中项目是指供考生参考的陈述的一部分或一组。这项研究调查了基于Thurstonian IRT（TIRT）模型的三种替代MFC项目的DIF检测，并使用了载荷和阈值的综合Wald检验。在广泛的蒙特卡洛研究中，我们研究了具有不同类型和大小的DIF，潜在性状相关性，样本量以及影响程度的受限和免费基线模型比较策略。结果表明，免费基线策略在检测DIF方面非常有效，在大样本量和大范围DIF条件下，功效接近1.0，在撞击和无撞击条件下的功效相似。