The invention relates to a method for monitoring at least one message, each message being associated with an action generated by at least one element or user of an information system (1000), said message(s) being collected by at least one message collecting device of the IS. According to the invention, the method comprises the step of defining a plurality of reference event categories each associated with at least one reference action from an ontology based on an intention class that characterizes the purpose of each reference action, an activity type class that qualifies the nature of each reference action, a movement class that characterizes the means for implementing each reference action, a target class that characterizes the object of each reference action, and a gain class that characterizes the result of each reference action.