The term "Flow Experiences" refers to periods of deep, intense involvement in activities that challenge but do not overwhelm one's skills. As conceptualized by M. Csikszentmihalyi (1990), Flow represents a distinct state of consciousness that integrates high but effortless concentration, intrinsic motivation, loss of awareness of self and clock time, facile response to challenge, and feelings of competence and freedom. This paper outlines some of the critical issues involved in assessing Flow, along with ways of addressing these issues. It then summarizes a preliminary examination of the validity of an instrument developed to assess activities that provide Flow experiences. One approach to assessing Flow has been the Experience Sampling Method, a naturalistic research method that uses paging devices to capture "snapshots" of momentary experience. Subjects respond about their experiences when they are paged at random. The piloted instrument, the Flow Activities Assessment, uses quoted statements to evoke the Flow experience and identify Flow-related activities. The questionnaire, which considered mathematical and literary activities, was sent to 900 academically talented students attending a summer session sponsored by the Center for Talent Development at Northwestern University (Illinois). Preliminary analysis of responses from 251 students indicate that the instrument discriminates the dominant experiences associated with different activities and helps students assess which activities integrate these experiences toward Flow. As a tool for research the Flow Activities Assessment needs further refinement, but early results support its potential. The instrument is attached. (Contains 1 figure, 3 tables, and 16 references.) (SLD)