Operationalizing "trance" I: Rationale and research using a psychophenomenological approach

Despite the popularity of the term "trance" among clinicians to describe th e subjective effects associated with being hypnotized, heretofore there has been no means to operationalize that definition. The authors present a rat ionale and psychophenomenological method to operationalize the term "trance " in terms of (a) hypnotic depth, a quantitative measure of subjective tran ce assessed via a pHGS (predicted Harvard Group Scale) score, derived from regression analysis, and (b) "trance typology profiles," a qualitative diff erentiation of empirically derived (via cluster and discriminant analyses) categories of subjective trance experiences. The authors then discuss theor etical and clinical implications of this psychophenomenological approach fo r developing an operational definition of the concept of trance.