Saris, Satorra, and Coenders (2004) proposed a new approach to estimate the quality of survey questions, combining the advantages of 2 existing approaches: the multitrait-multimethod (MTMM) and the split-ballot (SB) ones. Implemented in practice, this new approach led to frequent problems of nonconvergence and improper solutions. This article uses Monte Carlo simulations to understand why the SB-MTMM is working well in some cases but not in others. The number of SB groups is a crucial element: The 3-group design is performing better. However, the 2-group design can also perform well: The analyses suggest that the interaction between the absolute values of the correlations between the traits and the relative values of the different correlations between traits plays an important role. (Contains 9 tables, 1 figure, and 12 footnotes.)