The redundant aspect of communication becomes structure, providing the means for a communication to be recognized as belonging to the system. The event relies on this recognition for its inclusion as communication belonging to the system. ‘Redundancies . . . do not only exclude information, but also produce it by specifying the sensitivity of the system.’ At the same time as the system is able to distinguish structures and events according to their relevance for the system, it also communicates its own capacity to make such distinctions when confronted with different events in its environment. In addition, the aspect of the event (or new information) which is recognized by the system, which is accepted rather than excluded, now becomes part of the structure of the system. Any future identical situations in the system’s environment will no longer provide new information for the system. The relationship between redundancy and information may, therefore, be seen as ‘learning’ by the system. (49-50)
For instance, if information has been recognized (accepted) by the mass media system, the repetition of that information–a “future identical situation in the system’s environment”–will not have any information value for the system. The meaning remains, but there is no information value. No system learning is called for.
If structure (expectational structure) arises from redundancy, we might say that repetition of the same creates or sustains structure. The same kind of events are repeated, and this builds up structure; the system comes to expect more of the same. Without structures, events emerge and pass away in the same moment. Structure brings in the temporal dimension, establishing a before and after for an event. But repeated events make recognizable structures/patterns. Ritual (e.g., a marriage ceremony, funeral, Catholic mass) is all about redundancy. In any ritual, observers always know what is coming next, or at least what is supposed to come next, and they know if something is done improperly or out of sequence.
In liminal conditions, or transitions from one structure to another, redundancy threatens to dissolve; we don’t know what to expect next but we know that we can’t go back. This is where time (or temporal observation) comes into play. An event occur and there is no going back. Something changes and the change can’t be undone. Time is how long it takes for a change to be irreversible. Cultures create ceremonies to help people through liminal conditions, or difficult transitions like birth, adolescence, college graduation, marriage, death, etc. If a loved one dies, at least we know what is expected: We are expected to make phone calls, start planning a funeral, etc. A death is an event, and the expected ceremonies surrounding death are structures.
According to Luhmann,
Redundancy does not simply mean ‘superfluousness’ in securing message transmission against disturbances (noise) from outside but the saving of avoidable (and in this sense superfluous) information work.Organization and Decision, p. 37