I have never labelled myself as a sociologist but I did struggle through a masters degree in sociology many years ago and still have some scattered memories of the sorts of issues that sociologists talk about.

The principal insight gained from these studies has been the fact that social control and good order can be achieved by the use of informal methods without resort to the traditional criminal justice system of police, courts and corrective services. Informal social control is largely established by the members acquiring the attitudes and behaviours of other members. The process of acquisition may be, to a considerable extent, unconscious.

There may be some elements of reward and punishment, delivered principally by facial expressions or tone of voice, but in some circumstances may involve gaining or losing privileges. This is particularly the case in those closed institutions for which membership is involuntary, such as prisons and mental hospitals, but even there procedures are different from those found in the open community.

For most closed institutions, with the possible exception of some maximum security prisons, the number of supervisory staff is considerably fewer than the numbers of inmates or residents, which suggests that control is maintained by agreement or cooperation, rather than by force.

There are of course many other closed institutions beyond those mentioned so far, and others such as boarding schools, military bases and some experimental communities such as kibbutzim could be included. Possibly the ultimate closed community would be a team of scientists and their support staff spending a winter in Antarctica, but for the purposes of this article I would like to suggest that a much more pleasurable option be included: that of the tourist cruise ship.

Cruise ships are certainly closed communities when they are at sea sailing between ports of call and this may include periods of several days. It seems that social control on a cruise ship is largely achieved by a complex process of ensuring that passengers conform to basic rules and accept the authority of the captain and crew. All of this takes place within the context of maintaining the safety of passengers and ensuring that they have an enjoyable experience.

The process starts very early in the cruise. Within an hour of embarking, passengers are required to report to designated muster stations with their life-jackets, where they are addressed at some length by the captain (over the ship's public address system) who outlines the standard procedures for responding to a ''man overboard'' crisis and other emergencies. He provides details of the dress codes, times of meals and so on, and even gives instructions about how to use the toilets! The assembled groups of passengers are then taught how to put on their life jackets.

At the time of embarkation passengers are issued with their cruise cards, which are of central importance. The cards are the keys to your cabin (sorry, I mean state room), and are required to verify your identity every time you leave and return to the ship. They also act as credit cards for the purchase of alcohol and other items from the shops on the ship. The colour of the cards also indicates the status of passengers, which depends on the extent of previous cruising.

The cruise cards also indicate the assigned dining room for each passenger and the table number for dinner, which remains constant for the duration of the cruise. This means that passengers have the same dining companions each night whether they are compatible or not. The possibility of changing table for dinner is not offered, even though it must be possible.

The dress codes for the evening meal are spelled out in the ship's daily newsletter. On most days the code is ''smart casual'' which means men must not wear shorts for dinner, not even with long socks, while ''formal'' requires all men to wear jackets and ties, preferably dinner suits with black bow ties, while women are expected to wear long dresses or suitable pants suits.

For lunch and breakfasts in the main dining rooms, all passengers must be seated every time by senior staff, and the question: ''May I assist you, sir?'' will be addressed in a loud and authoritarian voice to any unfortunate male who tries to avoid this little ceremony.

These rules are reinforced by numerous written signs, both in one's stateroom and in common areas such as around swimming pools, where all running, jumping and diving is strictly verboten.

One of the results of this torrent of rules is that passengers generally conform to the expected standards of behaviour and dress without complaint and, in many cases, see the need for conformity as contributing to their overall pleasure with the cruising experience, as well as enhancing their safety. They also see the captain as the ultimate authority.

This subtle conditioning process may lead to an unexpected result: the belief that the captain maintains control by ordering passengers who break the rules to leave the ship at the next port of call. This is the subject of extensive gossip among many of the passengers, but it is never confirmed by the captain or other senior staff. It does not really matter whether this practice actually occurs; it is the belief that contributes to good order on the ship.

Finally, it must be said that the study of informal social control mechanisms in closed communities reinforces the obvious fact that in open communities, where most of us live, informal practices are far more influential on the totality of our behaviour than is the operation of criminal justice systems.

David Biles is a Canberra-based consultant criminologist who recently went on a cruise in the South Pacific.