Investigations of phonemic and semantic fluency suggest that these tasks yield different patterns of behavioral performance in people diagnosed with a variety of neurological and psychiatric illnesses. In an effort to better understand variations in total word production, a number of groups have also attempted to identify components of fluency performance. Measures of response clustering and switching have gained the most attention and have been posited to represent semantic/temporal lobe and executive/frontal lobe systems, respectively. Results from two recent investigations that employed measures of clustering and switching, one involving people with schizophrenia and the other people with various forms of neurodegenerative dementia, will be presented to highlight the strengths and weaknesses of this technique. Our results suggest that some measures of response clustering provide a useful index of semantic memory but that switching scores represent broader array of component processes and tend to show a more generalized pattern of deficit.