Brannick, M. T., & Spector, P. E. (1990). Estimation problems in the block-diagonal model of the multitrait-multimethod matrix. Applied Psychological Measurement, 14, Abstract.

Examines the most popular method used to analyze the multitrait-multimethod (MTMM) matrix, the confirmatory factor analysis (CFA), in which trait effects, trait correlations, method effects, and method correlations are simultaneously estimated. Analysis of published data from 18 correlation matrices showed estimation problems in all but one case. Simulations were used to show how identification and specification difficulties may account for these problems. Even trivial misspecification of a single parameter can prevent program convergence. It is contended that these problems render the CFA block-diagonal approach to analyzing MTMM data less useful than has generally been thought. (Copyright 1990, Sage Publications.)