Psychometric properties of the Mid-Range Expanded Trail Making Test. An examination of learning-disabled and non-learning-disabled children.

By systematically varying the stimuli within the Mid-Range Trail Making Test (MTMT), it may eventually be possible to isolate the cognitive demands of this test. Toward this end, the Mid-Range Expanded TMT (METMT) was developed by adding five new forms to the original forms A and B. To insure its appropriateness for clinical and experimental use, the current study sought to quantify the psychometric properties of this new test. The results indicate that the METMT is reliable and has adequate construct, criterion, and factoral validity. The results also cross-validated the findings of Davis et al. [J. Clin. Psychol. 45 (1989) 423.], suggesting that brief neuropsychological evaluations can effectively differentiate normal learners from learning-disabled children. The present study suggests that the MTMT is robust to alterations of its stimulus dimensions. Preliminary METMT normative data are presented.