Three trail making tests for use in neuropsychological assessments with brief intertest intervals.

Practice effects in serial neuropsychological assessment have led to the use of alternate forms to measure change in cognitive functioning. The construct validity of three variants of the Trail Making Test was explored over a 3-week period in a sample of 158 undergraduate students. Using confirmatory factor analysis, a two-factor (sequencing-shifting) model was identified to best represent the data. Latent means structural analysis indicated the absence of order effects, lending support for the construct validity of the three tests. The study provides evidence that the three tests can be offered as potential alternative instruments in serial assessment.