A recent investigation of the dynamic feature of the Minnesota Multiphasic Personality Inventory (MMPI)-based classification scheme for criminal offenders concluded that the system was unreliable. The purpose of this article is to challenge these conclusions based on an examination of the following problems in the methodology that was employed: (a) sample characteristics and biases, (b) procedures, and (c) lack of collateral data. It is recommended that future investigations correct the shortcomings discussed in an attempt to determine if changes in MMPI classification accurately reflect changes in the offender's adjustment, attitudes, or behavior.