Normative data for clustering and switching on verbal fluency tasks.

Normative data for clustering and switching on verbal fluency tasks are provided. Four hundred and eleven healthy adults between the ages of 18 and 91 were given tests of phonemic fluency (FAS or CFL) and semantic fluency (Animals and Supermarket). Raw scores were corrected for demographic (i.e., age, education, and sex) and test (i.e., fluency form) variables that were determined to make sizable contributions to fluency performance. These normative data should be useful for clinicians and researchers in determining the nature of the fluency impairment in any given individual.