The Minnesota Test of Critical Thinking (MTCT) has been designed to measure both critical thinking (CT) skills and a key disposition of critical reasoning: the willingness to evaluate arguments that are congruent with one's own goals and beliefs critically. The MTCT uses a taxonomy of CT skills derived from the American Philosophical Association's "Critical Thinking: A Statement of Expert Consensus for Purposes of Educational Assessment and Instruction" (1990). Preservice teachers in training (n=210) were administered one of two forms of the MTCT by random assignment. Initial results indicate an overall Cronbach's alpha for form A of 0.76 and for form B of 0.69. These levels of internal consistency are perhaps appropriate in testing a construct that is itself multi-factor, and the levels are in the upper range when compared with other tests of CT. Examination of the correlation matrix of the subscales as well as the factor structure of the test indicates support for a hypothesized structure of CT with three aspects: metacognitive, analytic, and communicative. The instability of the subscale scores indicates the need for caution in interpretation, however. These results indicate the MTCT has potential for measuring CT skills, but could benefit from further revision and refinement. The results also indicate the need for increased research into the structure of CT. (Contains 29 references.) (Author/SLD)