Describes elementary graph theory statistics, features that characterize differences in cognitive study strategies, and the use of STUDY for gathering trace data for research on patterns of cognition. STUDY affords a high degree of learner control and is an excellent medium for collecting data on individual differences. STUDY users navigate through content and apply studying actions such as underlining, taking notes, requesting elaborations, and attempting test items. As this happens, STUDY creates detailed time-stamped records of the learner's interactions in a log file. This sequence of study actions is reduced to a set of nodes representing action types and a set of links representing a temporal relation. The output of STUDY can yield resemblance statistics that can allow comparison of single actions by a student as well as comparison across students to reveal differences in cognitive processing routines. (French abstract) (PsycLIT Database Copyright 1995 American Psychological Assn, all rights reserved)