On the night of the debate, Greg Beswick set up his tape recorder by the television set and prepared to watch and listen -- and then listen again when it was over. "Tonight," as he said, "is going to be very important as far as I'm concerned." So it would prove to be, for him at least, if not the nation.

Greg is a student at Northeastern University, married and a Vietnam veteran. Typically, he had not made up his mind about which presidential candidate to choose Tuesday. Four years ago he voted for Jimmy Carter. He hasn't been happy with the president's record.

"The big problem we have in our country," he says, "foreign policy aside, is, of course, inflation. Quite frankly, Carter hasn't done much to stem the tide, so to speak."

But that concern has been outweighed in his mind by a larger one, and it is one that has become increasingly critical in the minds of Americans who will go to the polls in two more days -- the question of war and peace. "One big factor," he says, "is -- well, let's face it, for the last four years we've been at peace.And that's a very strong consideration. Reagan kind of scares me. I don't really know how to take the man. Sometimes he says things that are quite frightening."

When Greg talks about Carter, he's highly critical. One of the big differences, he thinks, between the Carter he supported in 1976 and now is a sense of the president, the presence he creates, or lack of it. "When he took office," he explains, "he was out all the time. He was very visual -- doing his town meetings and so forth. But in the last year or so it's just like he almost went into hiding. Of course, he was using the hostage situation by staying in the White House. I definitely think we need a change. The question is whether we need a change in the man or a change in the policy with the same man."

Still, for all his doubts, Beswick was inclined to vote for Carter as he settled in to watch the debate. As he said, "I'm leaning towards Carter for the reasons of peace."

Mark Gardner is another who looked to the debate as a moment of judgement. At 22, a business student who hopes to work in hotel and restaurant franchises worldwide, Gardner is an energetic open-faced young man who bubbles with enthusiasm. When he first begins speaking, you think you're in the presence of a solid Reagan backer. As with so many other aspects of American political attitudes this election, that initial assumption is wrong. "I like some of the philosophies behind Reagan's campaign," he begins. "See, I'm a business student and I like some of his business policies."

But, like Greg Beswick, Mark Gardner sees the 1980 presidential election in a larger context, and for some of the same reasons. "I definitely worry about Reagan's attitude towards the nuclear race with Russia," he says. "Carter, I'm not as afraid of. He's been very light with his dealings with foreign policy. I can feel he doesn't want to put his hand too deeply in the pot. Whereas Mr. Anderson, he's someone whose political philosophies are all right, too."

Gardner is one of those who would like to vote for Anderson, but is troubled by what that vote would do. "If you'd like to see Mr. Carter in office," he says, "it definitely will hurt to vote for Mr. Anderson."

At the same time he was frankly torn. "It's a vital election in the way the country's going to turn," he believes. "There are two types of different philosophies being used in the campaign with Mr. Reagan and Mr. Carter. Mr. Reagan definitely is concerned with foreign policy, although I'm not sure exactly how much he knows about foreign policy. But we also have to deal with our own country, and the way our own people feel about our own country. If the government is going to work for people, people have to feel the government is good -- and that's a change in attitudes we need.

"Right now there isn't a big stress by Carter or Reagan on this, whereas there was more stress put by Mr. Anderson. Everybody talks about taxes -- taxes being too high, and how outrageous it is. But if there are big cuts, who's going to be affected by them? I'm worrying about multinational corporations. Reagan's policy wants to turn more benefits over to big business, but they're trying to cut people off. Right now there are many court battles going on over pension plans. The young are replacing the old and the old are not that old. Some of them are done with their careers by the time they're 45 or 50 years old. Well, they have to turn to something else. As I've been taught, the older people always made the bigger decisions. Now it's turning more to the younger generation, people in their mid-30s, maybe 40s. I'm definitely looking at the way our own government is going to turn on these things.

Gardner had come up to the night of the debate virtually certain he wouldn't vote for Reagan. But as he said, "I'm still iffy on Anderson and Carter." He, too, was inclined toward Carter. It was the more practical way to vote. But he planned to watch the debate -- and John Anderson's appearance afterward, too -- before finally making up his mind. "It most definitely will make a big difference," he said. The Students

In a city of colleges, the great, the famous and the powerful, Northeastern University sits along the trolley tracks largely overlooked by the trendsetters who like to know, or think they know, "what Harvard thinks" or "MIT thinks" or other institutions, perhaps not quite so exalted but esteemed nonetheless, think. Throughout this century the working-class people of Boston and its environs have been going to Northeastern, many of them at night, to better themselves in their careers. They still are. Over the generations, some of the progeny -- people such as Theodore H. White, the writer and chronicler of American politics, whose father got his law degree at Northeastern by studying nights -- have moved up to Harvard, but Northeastern remains a large professional training ground for young men and women. Most of today's some 45,000 students commute to school from home each day (or night), Mark Gardner and Greg Beswick amoung them. In terms of national recognition and influence, they are not, as Lyndon Johnson used to say, both enviously and contemptuously, "the Harvards," but they are probably closer to the bone of the country.

Since 1972, when 18-year-olds became eligible to vote for president, the prospect of America's youth forming a decisive factor on election days has proved illusory. In a nation that celebrates -- worships, to be more accurate -- youth in dress, style and, supposedly, thought, and in all manner of life tries somewhat pathetically to pattern its behavior after "The Young," politics has been a backward movement in the great trend. On the last two presidential election days the percentage of young people voting has been the lowest of any eligible age group. Not surprising, either, for the young, as always, have had other, more pressing concerns -- mainly themselves.

That isn't to depreciate them, or to minimize their importance. This year in particular, where it literally appears every vote will count far more than normally, the way young Americans go to the polls -- or don't -- obviously is significant. Equally obviously, their attitudes are important for what clues they offer about the future, when they will be making the decisions and shaping the national agenda.

Northeastern is no hotbed of political activity; certainly it can't be compared in the same breath with the Berkeleys and the Columbias when it comes to setting a tone of collegiate activism with national implications. But the Northeastern students you meet are instructive. Those that say they are planning to vote -- and my random sample the past few days turned up about one out of two in that category, probably too high a percentage -- have as shrewd a grasp of issues and as unsparing a view of the candidates as their more experienced elders throughout the country. And they have been just as troubled by the nature of this election.

Three things are most striking about the conversations with young voters here -- their great concern over the possibility of war, their general unease about the state of the economy and what kind of life they will have in it, and their way of wrestlng out which of those concerns trouble them most and affects how they will vote.

By the time you reach here, after nearly two months of traveling in every section of the country, it's clear that the apprehensions about war have become an overriding concern among Americans. Reagan's candidacy has suffered because of it: The seeds of doubt about his possible presidential actions have been planted effectively. To win, he must reassure those who are troubled by what they think, or have heard, about him.

This appears especially true amoung the students, and most notably women. Women, for instance, seem to have reached their final decisions about Reagan faster than their male counterparts.

Lynn Buckley, for example. She's 22, dark-haired, a graduate nurse, whose serious demeanor disguises a sharp sense of humor. This will be her first presidential vote.

"I'm afraid of Reagan," she says. "I think he's going to get us into a war because he's already messed up so many things he's said. I wanted to vote for Anderson, but I'm afraid if I vote for Anderson it's going to put Reagan in, so I'm going to stick with Carter." To her, this election is very important. "There are so many things going on in the world right now," she says. "And everybody is in a nuclear arms race. I'm afraid things are going to blow sky high during this next term. It's going to be sink or swim in the next four years."

She's fairly typical in another sense -- she's not too enthusiastic about Carter and is quite critical of his handling of the hostage situation. "I can't see why the United States let itself get walked on like this," she says, referring to Iran. "Those 50 guys have spent almost a year in jail, and I can't believe it."

Nor is she against Reagan because of women's issues, and his opposition to the Equal Rights Amendment. "I'm not holding a banner for ERA," she says. "I believe we should get paid the same, and 'm for equal rights and against sex discrimination. But as far as going into the army and holding a gun on the front lines, no. If the draft ever comes down to females, since I just graduated from nursing school I would be drafted. I would be in a base hospital. So far as the Equal Rights Amendment goes, no, I don't want that. Equal pay and no discrimination, yes."

But when it comes down to a final choice, she's certain. "Of the two, Carter's trying the most," she says. "He still has a lot to know. I mean, nobody can prepare for that job. He is honest. He makes mistakes, yes. I think he made a mistake by bringing in a lot of the people from Georgia where he had a lot of top people in Washington already. He learned that a little late, but maybe this term if he gets in he'll rectify the situation."

Dottie Pellegrini and Maggie Watson are among numbers of other Northeastern women who have similar views.

"I think there's a possibility for war," says Pelligrini. "I think if we have Reagan we'll definitely go to war. He wants to build up that military budget to no end." She, too, started out preferring Anderson, but has changed. "I'm not sure about him and I definitely don't want Reagan, so I'll probably go for Carter so Reagan won't come in, she explains. "Even though Reagan did help California cut the rates and everything, he also cut a lot of services. I'm an education major and I'm really concerned about the human element. So you figure the special ed programs -- and a lot of other programs people need -- get cut down. Carter? They say he'd make a great neighbor, but ummmm, I don't know. He's a nice guy.He hasn't done too bad. Domestically he's kind of fouled up, but give him time. I don't know, I trust him more than Reagan and John Anderson seems a lot of fire and brimstone. I don't know him fully. He's still an enigma."

The defection from Anderson could be carted in the actions for Maggie Watson. "I was going to vote for Anderson," she says, "but now I think he's a fraud after hearing about the way he acted in Congress, putting bills through to make God the supreme ruler of the United States. I can see someone having a turnaround, [being born again] but not that abruptly."

She also sees the election in war-and-peace terms. "I think we're in trouble," she says. "I think foreign policy is the biggest issue." Her vote for Carter comes down to this: "Carter's much more careful than Reagan." She was sitting in the crowded student lounge, and added:

'A lot of my friends are voting -- and voting against Reagan."

To which a young man seated across from her replied:

"That's interesting. A lot of my friends are voting against Carter."

In that exchange between one young man and one young woman lay some of the larger political currents of this election. The Decision

"Volatility" has been the political cliche of 1980, and the wild swings of the undecided voters are supposed to be a phenomenon of the year. It's true a remarkably large number of people have been unsure about how to vote this time. rIn nearly every other presidential election over the last 20 years, when people said they were undecided they usually were not being candid; they knew exactly for whom they would vote, and usually quite early on, but preferred not to say.

In the last few weeks, as this election drew toward its end, fewer and fewer were truly undecided. Most you met who place themselves in that category were leaning clearly toward Carter or Reagan, and needed only some final reassurance to help them vote the way they really wanted anyway. That, at least, seems to be what happened, in miniature, with the Tuesday night debate. lSome of those absolutely set in their votes -- Maggie Watson and Lynn Buckley -- didn't watch. But for some of those really wavering the debate was crucial -- and in two of those cases, at least, surprising.

Greg Beswick watched and listened and recorded, all as planned. When it was over, he found himself completely from where he had begun. "I think it's going to be Reagan," he said, early the next morning. "He did a number on Carter last night. He was better able to explain his positions. It changed my views quite a bit."

He paused, and said:

"As you know, the war or peace question was vital to me. Maybe the things I had heard about Reagan being dangerous were distorted. He did not present himself as that kind of person last night."

The second of the undecided voters was Mark Gardner. He also followed his plan, and watched not only Carter and Reagan, but Anderson afterward. He found Carter better than Reagan:

"Mr. Carter looked more the part, more dignified, than I have seen him in a while. I didn't like what Reagan said about ERA, and I didn't like at all the way he consigned blacks to a lower minimum wage."

But that wasn't the big change for Gardner. "I liked Mr. Anderson," he said. "I thought he was the best of the three. He spelled out his thoughts better. I still feel threatened by Mr. Reagan's ideas on war and peace, but I just can't worry about that. I have to vote my piece for someone I really want. I will vote for John Anderson." The Election

The point is not to show, in some foolish instant mdeia survey, who "won" or "lost" the debate, thereby guaranteeing who will be elected president Tuesday. But the students here do demonstrate something important. They show how seriously they have been taking the election, how closely they have been assessing how to cast their votes (and why, even, to change them) almost up to the last moment. That would not have been the case of college students in my generation, nor even of their more publicized, supposedly more politically astute, older brothers and sisters when they were on America's campuses.

What's happened here in the closing days of the campaign is what I suspect took place in all the other areas visited earlier on this trip: Those who wanted reassurance from Reagan found it in his performance Tuesday night. Those who thought Carter the more prudent, able man were reinforced in their belief. Those who looked for a reason to vote their hearts and go for Anderson ended the feeling positive about supporting the person they really wanted.

Perhaps more important, in this season of negative attitudes about America's presidential prospects, the students at Northeastern reaffirmed a strain encountered elsewhere -- the conviction that, complex as national problems are, and frightening as some of the worldwide portents, there are still many individual citizens who believe their effots count, that they can make a difference.

David I. Rabinovitz is one. He's a lean, intense type who lives in Stoughton. "I made a very concentrated effort to make sure I was registered to vote," he says.

He thinks the country is approaching a critical period. "Everyone wants a change," he says, "and people want to turn things around and go in another direction. It's going to happen. If it doesn't happen in this election, it's going to happen in the next. And I just want to make sure my vote is counted on which way we go."

He is, by the way, for Carter. That's not an editorial nudge in the president's direction, nor a clue to how the results will turn out Tuesday. It's merely a wary journalist's way of avoiding taking a stand by hiding behind a cowardly statement of fact.