“…Examples of three kinds of rescheduling follow. First, a natural behavior may be elicited by the researcher without destroying its natural quality, for example, eye contact (Ashear & Snortum, 1971), activity level (Wolfensberger, Miller, Foshee, & Cromwell, 1962), or lateral eye movements (Gur, 1975). In such studies the measurement must be unobtrusive.…”