The purpose of this study was twofold: (a) to examine whether the unidimensional adaptive testing estimates are comparable for different ability levels of examinees when the true examinee-item interaction is correctly modeled using a compensatory multidimensional item response theory (MIRT) model; and (b) to investigate the effects of adaptive testing estimation when the procedure of item selection of computerized adaptive testing (CAT) is controlled by either content-balancing or selecting the most informative item in a user specified direction at the current estimate of unidimensional ability. A series of Monte Carlo simulations were conducted in this study. Deviation from the reference composite angle was used as an index of the theta1,theta2-composite consistency across the different levels of unidimensional CAT estimates. In addition, the effect of the content-balancing item selection procedure and the fixed-direction item selection procedure were compared across the different ability levels. The characteristics of item selection, test information and the relationship between unidimensional and multidimensional models were also investigated. In addition to employing statistical analysis to examine the robustness of the CAT procedure violations of unidimensionality, this research also included graphical analyses to present the results. The results were summarized as follows: (a) the reference angles for the no-control-item-selection method were disparate across the unidimensional ability groups; (b) the unidimensional CAT estimates from the content-balancing item selection method did not offer much improvement; (c) the fixed-direction-item selection method did provide greater consistency for the unidimensional CAT estimates across the different levels of ability; (d) and, increasing the CAT test length did not provide greater score scale consistency. Based on the results of this study, the following conclusions were drawn: (a) without any controlling (PsycINFO Database Record (c) 2003 APA, all rights reserved).