Presidential press conferences often appear to have been designed by a madcap choreographer with all those leapers clamoring for the attention of the imperturbable central character.

From another view, the conferences have much in common with cocktail parties: both are 20th century inventions, the host can pay off a lot of obligations quickly, any serious or unpleasant discussion can be avoided by changing the subject, nothing is likely to be explored in depth, there is great temptation to make something out of not very much, and both host and guests are relieved when the thing is over.

Still, when all possibilities of caricature are exhausted, there are few reporters or presidents who are willing to propose or make press conference changes.

Ray Jenkins, deputy to Press Secretary Jody Powell, says he would rather try to settle the Sino-Russian border dispute than tinker with the format. George Reedy, who began his presidential experience with Franklin Roosevelt and was President Johnson's press secretary, says, with a touch of regret, "There's not much that can be done about it." Veteran Washington newsman Chalmers Roberts says there is not a way, nor should there be, to stop the kooky or embarrassing or even stupid questions that sometimes get directed to the president.

Jenkins, Reedy and Roberts defend the conferences, although all have a certain uneasiness about them. They, and others, agree that something extraordinarily important is going on when the president faces the press, regardless of whether there is major news to announce.

The reason is television, which has been a major element in the press conferences since the Kennedy administration. Via television, the press and public see the president in action, facing a barrage of questions, fielding them, reacting quickly or thoughtfully, communicating confidence, reluctance, chagrin, patience or impatience, humor or anger. It is the image of a president under fire, and his words are frequently not so important as how he is perceived to be handling them.

Never mind that the president is, but the nature of the confernece, in complete control. It is his show. He can select the questioner, answer or not as he pleases and turn his answers, regardless of the question, to whatever he wants to pursue.

And, also, never mind that the networks play games, pulling their cameras into tight shots of their own reporters. Right there. Right there! Hello all of you affiliates across the country. We are here, right where the action is, on the front lines! Whooee.

It is a circus in a sense, but it is a serious, even a vital circus. It conveys a sense of the president and, through him, a sense of the country.

President-elect Reagan promises press conferences "at regular intervals." How regular is still to be decided, but he was accessible as governor of California. Awaiting him is a report, months in the making, by experienced journalists and public figures who have suggestions on how to reduce press conference spectacle. Clearly that kind of modificatin is needed.

But the traditinal press conference, even if slightly altered, is not enough. More informal, relaxed sessions are necessary if the press is to measure the longer rhythms of the man, his reflections, his plans, his hopes, how he sees the world and the country and, if he is strong enough to let his humanity show, some of his doubts and uncertainties.

These sessions can take any number of forms. Franklin Roosevelt used "deep backgrounders." Lyndon Johnson followed George Reedy's advice and called "quickies," inviting in, without notice, any reporters who happened to be around. Jimmy Carter had 600 "press contacts." John Kennedy talked frequently and deeply with members of the press. Dwight Eisenhower did less of it, and everybody could understand what he said even if his sentences didn't parse. Harry Truman ruminated to breathless reporters trying to keep up with his breakneck walking pace.

These reflective sessions are not the stuff of the 30-minute circuses, but they are essential if the press is to convey the full measure of the man in office.