Verbal fluency task equivalence

The research and clinical use of the verbal fluency paradigm has been hindered by the paucity of information on the equivalency of the various versions of this measure. Currently, the comparability of the two most commonly used forms of the letter fluency task, the ''FAS'' and ''CFL'' tests, is uncertain. The equivalence of these versions was investigated by examining their consistency across and within settings and disease processes. The two verbal fluency tasks were administered to 287 patients at two separate sites as part of a neuropsychological evaluation. Results showed that the CFL and FAS verbal fluency paradigms were equivalent across both settings and diagnostic groups with correlations ranging from .87 to .94. These findings may be useful for both researchers and clinicians who require equivalent measures for repeated testing. Furthermore, the demonstrated equivalency of the two paradigms may facilitate interpretation of research findings across laboratories.