1. A context-awareness system for use with a plurality of nodes, comprising: an event data producer means for receiving node data from the plurality of nodes and for forming, from node data including a node value relating to an event, event data including an event value converted from the node value; a context producer means for forming context information relating to the event from the event data; and an event data manager means for storing event data formation suppression information for suppressing a number of formations of event data per unit time depending on a number of entries of the event data into said context producer means per unit time and a priority order in forming the event data, the priority order being determined in advance, and for storing event data conversion rules for converting node values to event data for specific levels of event data formation suppression information, wherein said context producer means sends the number of entries of the event data per unit time to said event data manager means, wherein said event data manager means sends, from among the stored event data formation suppression information and event data conversion rules, event data formation suppression information that includes a priority order for forming the event data, and an event data conversion rule corresponding to the number of entries of the event data to said event data producer means, and wherein said event data producer means forms the event data based on the event data formation suppression information and the event data conversion rule sent from said event data manager means.