The comparative responsiveness to suggestions of 2 groups of subjects totalling 60 was studied in an effort to ascertain whether or not a formal induction of hypnosis has a specific enhancing influence upon suggestibility over a broad spectrum of response. For this purpose a special scale of responsiveness to suggestions was constructed and used. The results indicate that, when an induction of hypnosis is employed, some individuals show an appreciable change in suggestibility which is compatible with the notion long held that a change in state is brought about. This effect has a relatively low correlation with responsiveness to suggestion in the absence of an induction of hypnosis, a fact which strongly suggests the above is a unique property of the induction procedure. It is proposed that until a better criterion is found, the demonstration of a.signif icant increase in suggestibility following a formal induction of hypnosis might be used in deciding whether or not a person has been hypnotized, and would in any case help in communicating intelligently about hypnotic phenomena. There is evidence that the Stanford Hypnotic Susceptibility Scale can be directly used to select individuals who are and who are not affected by the induction procedure without having to resort to a pretest of "waking" suggestibility.