JOHN NAISBITT isn't a futurologist predicting smell-o-vision; he is a "social forecaster," basing his estimates of what will happen tomorrow on what is published in the newspaper today. Though he has made megabucks and sold megabooks off this concept, he isn't a megalomaniac. In fact, he seems regular, even low-key, despite the onslaught of fame and probable millions.

His book, "Megatrends," is a number one best seller, is in its 15th printing, and has sold half a million copies since October. But you might not pick him out as an author. What he looks like, with his elder-Beach-Boy's complexion, his full swath of reddish beard, is an Old Spice commercial. Actually, he grew up in the desert, Mormon country, but never mind: You could picture him on a 30-footer off Annapolis, instead of high on the seventh floor off Connecticut Avenue. They haven't hung all the pictures yet in here.

He wears pinstripe shirts and keeps his walking cash in a money clip. At lunch, he'll lean forward and draw maps and bar graphs on his placemat. He'll write notes to himself and tear off the edge of the mat. He is fairly reeking with his success, and it is nice to be around someone so sunny about it. People see him on the street and say, "Hi. Saw ya on the 'Today' show." It's a way of participating, he says.

Years ago, his Mormon elders were hoping he'd become a missionary. Not only did he not do that, he left Utah and the church, winding up in Chicago, and, later, Washington, living mainly by his wits. "I think I'm a son of perdition," he says, not joking. But he wasn't cast out, so far as he knows, and his mother still prays that her 54-year-old son, once divorced and now remarried, will come back to the faith.

Here, at the Naisbitt Group, in these still slightly tentative offices (where they have been since January), another kind of faith is being expressed--in something called "content analysis." This is a hot research and consulting firm, with a hot book on its hands--though like a lot of overnight success stories, this one took a decade and a half.

Requests for speeches now come in at 20 to 30 a clip. These days Naisbitt's 27-year-old daughter, Claire, who has come in to help while things are at floodstage, has to spread out on the floor by his desk the messages that just can't wait. They are like a pink flotilla, with exclamation marks, these scribbled messages, and when her father comes back from lunch he has to step over them to get to his chair. Claire, an artist, writes the best letters in the office, her father says.

"Well, I was always sure 'Megatrends' was going to be a best seller," he says, managing the trick of not sounding boastful. "I could see people out there were longing for structure about where we are and where we're going. I had been around the country giving too many speeches to too many CEOs chief executive officers not to know the people in our group were on to something. Heck, I would run into people in Sweden, for instance, who would tell me they had seen 14th-generation-Xeroxes of our Trend Reports. But to tell you the truth, I feel exactly as I felt before. I was making speeches before. I was spotting trends before. But the intensity. I feel sometimes as if I'm losing control of my life."

The people at Warner Books are going around saying to themselves: "Not since the Bible . . ."

And how utterly simple it all seems, this elucidation of the supposed sea changes going on in American society. "Megatrends" seems megasimple, nothing you didn't know, ipso facto obvious, and therein lies its genius, maybe. But therein also lies the criticism of it, though Naisbitt himself would reply to the charge of oversimplification that all he's done is order the chaos, "give some selection to the supply."

Incredible supply, for what we are swimming in right now, says the trend spotter, is "an increasingly diverse multiple-option society." That is a Naisbitt buzz phrase, along with "high-tech/high-touch" and some others. He's also very good at pithy lines, such as, "Trends, like horses, are easier to ride in the direction they are already going." Or: "We are drowning in information but starved for knowledge." Or: "Lawyers are like beavers: They get in the mainstream and dam it up."

In a word, Naisbitt analyzes a trend--say, a growing backlash to television, or the waxing of concern about crime--through the systematic reading and clipping and categorizing of millions of news items from thousands of individual copies of newspapers. Actually, content analysis is a technique as old as the hills. The news hole in a given paper on a given day is only so big, and if something comes in, then of necessity something must go out.

So if you analyze what is coming in and what is going out, country-wide, on a systematic basis, you start to pick up shifts and movements, a nation's worries. Trends, John Naisbitt says, are generated from the bottom up (though fads come from the top down). That is, America changes most substantively at the grass-roots level, contrary to what Washington and New York may think. And it is at the grass roots level that our social, political and industrial organizations are undergoing massive change.

Here is a John Naisbitt megatrend. In fact, it's Megatrend No. 1 (out of 10) in the book: We are in the throes of a shift from an industrial age to an information society, or, put another way, we are moving from an economy resting on the motor car to an economy resting on the computer. And, trend within trend, mega within mega, we are moving from the hardware revolution of computers to the software age of them.

So what else is new? Well, he has nine others.

"My data base is like putting every newspaper morgue in the United States in one pile," he says.

The OSS used content analysis in World War II to find out what was going on in the daily life of Nazi Germany. Historian-author Bruce Catton used the daily paper to reconstruct the Civil War. So did Stephen Crane, in his incomparable work of the imagination, "The Red Badge of Courage."

And in Denver and Stamford, Conn., and, to a lesser degree, in Washington, D.C., busy beavers of a different sort and purpose are sitting in little rooms, marking and clipping. All day long they clip and clip, mark and clip, approximately 250 papers, 6,000 articles a week, 20,000 a month, presumably inking their fingers for life in the service of the Naisbitt Group. The result of all the clipping and filing and then analyzing--the clips get sorted into 13 categories, then into 200 additional subcategories--is . . . Megatrend! It's a bird, it's a plane, it's . . .

"Actually, the biggest compliment people pay me is when they say, 'But I sort of knew all that.' Yes, the academics think it's too simple. I did get a nice note from Professor Daniel Bell at Harvard, though he may have just been acknowledging my stated debt to him in the front of the book. The New York Times review was very unhappy with my cheerfulness."

This cheerfulness about the future, not gloom and doom, is one of Naisbitt's distinguishing characteristics. Technology isn't going to kill us, he says. In fact, technology will make us free, make us reexplore the arts, the age-old questions. The future is going to be more exciting than ever, for "human beings always provide counter-ballast to technology, in spite of themselves." So the gospel according to Naisbitt is that the more high-tech, the more exploration of our humanity. And not to worry about Japan devouring us, either. "Our ethnic and intellectual mix is far richer, unlike the Japanese society, which is so monolithic." That will save us in the coming software age.

Who knows if it will turn out this way? As James Taub once wrote in Saturday Review: "Virtually the only subject that a futurologist will not talk about readily is his batting average."

In a sense, he is the unlikeliest of people to make his fortune forecasting. Once, it seems eons ago, he was a Washington bureaucrat trying to tunnel his way out. Among other jobs in Washington, he worked as a top aide to HEW Secretary John W. Gardner. In Chicago he started Urban Research, a consulting firm. He would jog along the lake front (sometimes in the company of another schemer, Muhammad Ali) and dream of bigger things. A couple of years ago he worked in Washington for the Yankelovich poll-taking firm. Somewhere in there, too, he had something called the Center for Policy Press.

In the spring of 1969, in Chicago, he had his moment of epiphany: He was reading a Bruce Catton book when it hit him that newspapers, even 100-year-old newspapers, can be primary source material. "I went immediately to an out-of-town newsstand and bought 60 papers." The megatrending of John Naisbitt and America had begun.

What is an example of a trend newspaper, he is asked. He brightens. "The Pacific Sun, Marin County, California. There's a cutting edge newspaper." He also thinks The Economist is a must for anybody doing his kind of work. And every day he reads The Washington Post, The New York Times and The Wall Street Journal. He seldom clips or marks up these days. Leave that to the troops.

"How to categorize without getting emotionally involved--ah, that's the art," he says.

Where does this ability to see the forest, to overview instead of underview, come from? He isn't sure himself, and instead gives this example:

"I was flying into National Airport once and we skimmed low over the trees, and it then hit me that the tallest building in Washington is not as tall as the tallest tree. That's why this place is so livable. It goes outward, not up." That's not a trend, but it is an abstraction.

The Utah desert went outward instead of up, too, and though he doesn't go back too much, home is a fond place. "My grandfather Sorenson, from Denmark, was a disciple of Brigham Young. Brigham sent him down to start the town of Glenwood, which is where I grew up. Three hundred people, incredibly isolated, incredibly rigid, incredibly loving.

"You know, Brigham Young was an organizational genius: every time a church got 300 members, he would order a splintering off. But I had to get out. At 19 I joined the Marines.

"And everything just happened after that."