Psychometric analysis of the Visual Form Discrimination Test.

The Visual Form Discrimination Test is a matching-to-sample test involving visual discrimination. Although normative information has been presented, limited psychometric data have been available. The current study estimated the internal consistency and additional psychometric properties of the test in a sample of 66 persons with acute traumatic brain injury. Internal consistency as measured by alpha was .66. A homogeneous sample and a restricted range of scores likely attenuated this estimate. Using the standard cutoff score, only 32% of the sample showed impaired performance. Visual form discrimination as measured by this test may be affected less by traumatic brain injury than other cognitive processes such as attention and memory.