Everyone has been very polite about the glorified joint press conferences that will serve as the 1984 campaign equivalents of presidential and vice presidential debates.

The showdowns between Ronald Reagan and Walter Mondale in Louisville Sunday and between George Bush and Geraldine Ferraro in Philadelphia the following Thursday have been planned by the League of Women Voters as serious discussions of policy issues.

The panels of reporters, who would not be needed if White House chief of staff and debate negotiator James A. Baker III had permitted Reagan or Bush to go into real debates, will ask the thoughtful questions that are expected of them.

But despite the good efforts of all these sincere people, most of us will be watching not to ge an education on the issues but to see how these four people play off against each other.

While the stakes are bigger in Sunday's Reagan-Mondale shootout, in some ways the personal chemistry of the vice presidential contest is more intriguing. Reagan and Mondale are both known quantities. Both have debated previously on national television, Reagan against Jimmy Carter and John Anderson in the two 1980 debates, and Mondale against Sen. Bob Dole in the 1976 vice presidential contest.

Mondale will be aggressive, partisan, sharp and specific, if he performs as he usually does. If Reagan is in form, he will be relaxed, affable, making his own points and sidestepping Mondale's barbs and the questioners' harpoons.

It will not be surprising if the Democratic challenger shows himself more knowledgeable on the issues than the incumbent. But Reagan always knows where the camera is, and he is more skilled than Mondale in talking past the questioners to the voters at home.

The matchup of Bush and Ferraro is less predictable. There's the obvious fact that she will be the first woman principal in the 24 years since Richard M. Nixon and John F. Kennedy inaugurated the series of televised debates.

But that is just the beginning. Ferraro is also the least experienced person ever to step onto the nationally televised debate stage, with only six years in elective office. Bush had a House career and a series of diplomatic and national security assignments before becoming vice president. In that post, he has been "in the loop" on all the major policy discussions, including last week's meeting with Soviet Foreign Minister Andrei Gromyko.

On the other hand, Ferraro is a nervy, intuitive and quick-tongued politician, ready to take risks and to rely on her own instincts.

Bush is none of those things. He can "freeze" under pressure, as he did when Reagan switched signals on him and invited the other Republican contenders to join in their Nashua, N.H., debate during the 1980 primaries.

Traveling with Ferraro and Bush last week, I thought it was clear that they are opposites. Her basic stump speech is a series of anti-Reagan one-liners, skimpy on subtlety but sharply barbed.

Bush, by contrast, is the gentle persuader, a man who says accurately that "I have never been a gut fighter." Whatever she does, he will not slap Ferraro down. More likely, if she comes in flailing away, he will be inclined to step back and see if she falls on her face.

But Bush cannot afford to backpedal throughout the debate. Reagan will expect a strong defense from his running mate. And the Republican activists around the country who will be eyeing Bush as a likely contender for the 1988 presidential nomination will be less forgiving of a weak performance than Reagan is likely to be.

For that reason, Ferraro is right when she says that Bush has more at stake than she does. But she has quite a lot -- no matter how much she may deny it. It is clear from the public polls and from the comments of voters that many people remain unconvinced that she has the experience or judgment to be a heartbeat away from the presidency. She created a strongly favorable first impression on the voters, when Mondale picked her for the job, but was soon caught up in controversy about her family finances and taxes and about her abortion views.

She handled those issues well, but people lack any rounded view of her. Her campaign appearances are no help, for Ferraro spends little time sketching her own background or approach before she launches into her attacks on Reagan's policies.

As her friend, Rep. Barbara Mikulski (D-Md.), said the other day, "When you're a woman, no one ever assumes you're qualified. . . . You have to talk about your background and let them know what you've done."

Ferraro has not done that so far in the campaign, and the debate with Bush may be her last chance.