Call it 'info-tainment' or 'docu-schlock,' this is popular TV

Just call it dessert. It follows the evening news like pudding after a TV dinner: A young, fresh-faced couple walks the living-room audience through the latest local fads, meets people with oddball hobbies, joins wacky local contests, and chats with local celebrities.

And they keep the conversation as light as whipped cream and Jell-O for an audience already sated with the day's newscast.

TV executives call it ''reality programming,'' like the news. But it isn't exactly news. Some call it ''info-tainment,'' meaning information that is entertaining. Others call it ''docu-schlock.''

Whatever one calls it, shows like this have swept the airwaves. By now, the local channels nearly everywhere in the country carry at least one soft-feature, magazine-style TV show.

It was all Bill Hillier's idea.

He conceived it as clever way out of a jam, but it has proved to be a versatile creature - so far - in all kinds of television markets and situations.

It started in San Francisco in 1976. Mr. Hillier, a Harvard-educated former documentary producer with a doctorate from the Carnegie Institute of Technology, was programming director for KPIX, the local CBS station. The station was concerned about its ratings in the half-hour slot following the national news.

In TV-programming jargon, this slot is ''prime-time access.'' The Federal Communications Commission ruled in the early '70s that the networks must leave this half-hour of prime time free for local programs.

A little ironically, local stations had promptly filled their ''prime-time access'' with syndicated game shows like ''Family Feud'' and ''The Newlywed Game.'' KPIX was no exception, and it led the local ratings for the 7:30-to-8 p.m. time slot.

But it was slipping. Mr. Hillier sensed people were getting tired of game shows. And game shows were getting more expensive to buy, putting pressure on the station's budget just as ratings were weakening.

The idea came as he was flipping through a newsmagazine and happened on an article about the ever-thickening success of slick, city-based magazines like Boston, New York, and Los Angeles Magazines. His concept was to translate the city-magazine premise onto the TV screen.

A few years earlier, this would have been an expensive notion. But in 1976, TV minicams were just coming into their own. Using these shoulder-held cameras, on-location filming became virtually as easy as walking around town, and cheaper than studio production.

The minicam made the magazine premise practical. The format could tap into viewers' appetite for information about their own locale, use as many visual settings as a crew could visit, and still meet the station's budget.

''Evening Magazine'' was popular enough in San Francisco its first year that Westinghouse, which owns KPIX, began airing it on the company's other stations in Boston, Pittsburgh, Philadelphia, and Baltimore. Each station produced some of its own local segments to splice in with the show's fare from San Francisco.

It was an idea whose time had come - right after the news and before prime time. In its third year, the show was rechristened ''PM Magazine'' and was syndicated to 46 stations around the country under a cooperative arrangement. Stations substituted their own local stories as they saw fit and sent in at least one video story a week for consideration in the national package.

The next year, ''PM'' was on 106 stations. It became the most highly syndicated first-run show in the country, trailing only ''M*A*S*H*'' reruns.

Flocks of ''PM Magazine'' clones started taking to the airwaves. Now at least 125 stations and all three networks produce their own versions of the PM-style format.

In Los Angeles, ''Eye on LA'' and ''Two on the Town'' do fierce battle every week-night to gain the edge in audience share. ''PM Magazine'' itself airs just afterward.

''Real People,'' ''That's Incredible,'' ''Ripley's Believe It or Not,'' ''Entertainment Tonight,'' ''Hour Magazine,'' and a host of others are all variations on the theme Bill Hillier founded.

''These magazine shows are a bonanza for the people who produce them,'' remarks Joe Saltzman, chairman of broadcast journalism at the University of Southern California. ''They cost a fraction of what an entertainment production takes.''

What concerns Mr. Saltzman is that audiences trust these shows like news programs, but the programs are produced with entertainment standards, rather than news standards. ''It's the general attitude that 'we don't have to be fair, because we're not news.' ''

However balanced and accurate, the magazine shows are a hit.

Can it last? Will these snappy three- to six-minute segments on juvenile sidewalk dancers, skyscraper parachutists, and soap-star Linda Evans start wearing thin?

There is such talk. Hillier himself says the form has passed its peak and needs fresh air, just as the game-show format once did.

''That's one of the questions we have to ask ourselves all the time,'' admits Mary Kellogg-Joslyn, programming director of the Los Angeles station that produces ''Two on the Town.''

So many ''PM'' look-alikes have appeared and newscasts have expanded so far into the soft-feature domain of the magazine show (since it's so cheap to produce) that - says ''PM's'' executive producer Dick Crew - ''You've got people doing 'PM' ahead of us, doing 'PM' behind us, and doing 'PM' against us.''

Now only 75 stations produce the show cooperatively and another 20 smaller ones just buy the national package intact.

''People watch TV in funny ways,'' notes Mr. Crew. At 10 p.m., he explains, people are more apt to sit and stare at the television. But at 7:30 or 8 p.m., they are more likely to watch while doing the dishes.

''Ours is sort of a settling-down period. People are paying about three-quarters of their attention, and the show needs to punch through what's going on in the time period.''

''PM's'' response: a shift to shorter, punchier segments; getting cutting-edge trend stories before the competition picks them up; adventure stories; and Hollywood celebrities.

Crew has found an ''incredible appetite'' among viewers for Hollywood stories. ''We went to the well on 'Flashdance' about five times,'' he recalls, doing segments on the movie itself and, successively, its impact on fashion, dance, exercise, and music.

Bill Hillier has applied the magazine recipe to a handful of new programs since he left ''PM Magazine'' in 1980. Currently he is producing ''EPCOT Magazine'' - a family-oriented show specializing in innovative ideas - for the Disney Channel on cable TV.

''Content is the key,'' says Hillier. For a magazine show to last, it needs good story ideas. To this end, some eight staff members at Hillier Productions search out story ideas full-time with the use of several computer data banks.

The great-ideas premise of ''EPCOT Magazine'' makes stories easy to come by anyway, he says. An earlier Hillier effort, ''World of People,'' folded because it simply ran out of the kind of events it presented.

Lawrence Taymor, ''EPCOT Magazine's'' producer, is a veteran of many magazine shows and their mad scramble for fresh story ideas. ''I've produced every story I see on those shows,'' or one very similar to it, Mr. Taymor says. First it's the Great Chili Cook-off, he says, and next it's the Great Chili and Onion Cook-off.

After three years with Los Angeles's ''Two on the Town,'' executive producer Kevin Meagher says the prime liability of the profession is that the staff has no life outside the show. Hours are long and consuming. ''Eat at a good restaurant,'' he says, ''and the first thing you think of is: 'This would make a good segment.' ''