Around this time, several linguistic studies began to acknowledge not only the presence, but importance of variability found in speaker data. Instead of dismissing this variability on the grounds that the variants either belonged to different coexisting linguistic systems or demonstrated unpredictable free variation as had been done before, they recognized that it might be influenced by the speaker's circumstances. Sociologist John L. Fischer conducted one of the first systematic studies of language variation in 1958 to address variation in the speech of New England schoolchildren. Finding free variation to be an unsatisfactory explanation, he wrote: