An investigation into high level event monitoring within the scope of a well-known multimedia application, HyperCard--a program on the Macintosh computer, is carried out. A monitoring system is defined as a system which automatically monitors usage of some activity and gathers statistics based on what is has observed. Monitor systems can give the authors of a program or system accurate statistics on how their product is being used. An attempt is made to gather and process user's actions at a high level, enabling accurate and quantitative statistical analysis to be performed. This type of information is either very difficult or impossible to obtain through other methods. The HyperCard monitor works by inserting itself in the HyperCard message-passing hierarchy and setting up handlers for all messages considered useful for data gathering. Monitor data can be used to analyze a particular user for a particular work session, or to offer a head to head comparison of users over many sessions. Overall, the HyperCard Monitor System was found to be very effective, and many of the general concepts used for the system could be extended to the operating system (OS) level if such an OS provided a facility for generating and interpreting high level events of this nature. Performance on a Macintosh Quadra 700 was very good and the resulting data output was very compact--tests revealed about 50k of data per user per half hour. Contains six references. (MAS)