The interview show was built around National Nutrition Week. The host's first question from the guest from the National Dairy Association was, "Why is nutrition so important that it has its own week?"

So it goes on Channel 8, the local-programming outlet on Reston's cable TV system. Though it is almost 7 years old, though it reaches more than half of the community's 9,500 households, Reston cable TV is still struggling to find its own identity as a hometown medium.

Some things Reston cable does very well. It sends a television picture of studio-monitor quality to its 5,400 subscribers, bringing in not only Washington's stations but Baltimore's too. For $6 month, on top of the regular $8.50 cable charge, it supplies recent movies, such as "Blazing Saddles" and "That's Entertainment, with no commercial interruption.

One channel provides time and temperature, 24 hour a day, another offers continuous tickertape news, though both of those services are available free through other media (the telephone and radio).

A rich and exciting variety of locally developed programming, the hope when cable TV came to the new town, has not materialized. In this disappointment, there may, or may not, be a portent for future cable operations in the metropolitan area.

After years of false starts, it appears that cable TV will be coming to the area in a big way. A private company in Arlington, granted a franchise by the county government, hopes to begin operation in late fall. Prince George's County has passed an ordinance clearing the way for approval of two franchises - they'll probably be granted with a year - and Montgomery County's own council received a smiliar ordinance last week.

Because most TV sets in the area already receive adequate TV reception, new cable operations will have to deliver at least part of the electronic cornucopia that has, been long-promised by the medium's publicists. That would include, besides such exotic services as providing burglar and fire alarm systems and push-button bill-paying, local programming that will attract viewers' attention.

The Reston experience offers some sobering lessons on the difficulties in establishing respectable local programming. Program director Tom Bartelt struggles along on a budget of $30,000 to $35,000 annually, out of which comes his salary and expenses for everything from light bulbs to studio furniture.

The minuscule budget means Bartelt must rely wholly on volunteers, on both sides of the camera. Someone who knocks on the studio door Monday asking for a job, may be operating a camera later in the week, if he or she isn't actually hosting a show. People who want to show off their musical talent don't find cable TV exposure difficult. "It might not be good enough to make it on Johnny Carson," Bartelt says, "but we put them on."

"Skeez," a program for 8-to-12 years olds, gained a wide following with its shows featuring local youngsters. It died not for lack of popularity but because volunteers, including parents who helped in production, didn't keep up the schedule of three and four-hour rehearsals for the half-hour program.

"The volunteers start with a lot of enthusiasm," Bartelt said, "but after a while, they want to know why they aren't getting paid, and they start drifting away."

One interview program - which died when the host moved out of town - attracted attention with occasionally provocative guests, including a woman who claimed to be a local prostitute. "Questions were asked that I've never heard asked on a network program," Bartelt said. "The community is more open to a whole range of ideas."

The range of ideas on current programming is not very wide. Last week, there was an interview program, repeated twice, featuring two officials of the Toastmasters Club.

Discussion of trepidations of speechmaking, one official said of Toastmaster training, "You won't get rid of the butterflies in your stomach, but you can make them fly in formation."

The Toastmasters show was followed by another interview program, this one on the subject of spring decorating. "Today we're not going to talk about any burning issues," host Janet Phelps said at the beginning. She kept her promise for the next half hour, her guests from a suburban furniture store talked about such things as the advantages of viscose fibers over acetates in a fabrics.

Next was a week-old tape of a Virginia Slims tennis tournament held in Dallas. The show was occasionally interrupted by public-service commercials for such groups as the Red Cross and American Cancer Society.

For five years, Mona Head has conducted an often stimulating interview program called the Head Show. On two recent shows she had black and white guests, of all age levels, discussing their reactions to the commercially televised "Roots" program.

Mrs. Head said she is disappointed by the quality of local programming. "I don't blame the people involved or the director, I blame the budget."

Tucked away in the back of an electronics factory that is near the Dulles Airport Access Road, far from Reston's two village centers, Reston cable TV has little public visibility. And there is no money allocated for promotion.

Arthur Arundel, the publisher of the thriving local newspaper, the Reston Times, decided not to carry the leg for local programming, apparently because the cable outlet is a potential competitor for subscribers and advertising dollars - a specter that doesn't appear to be too threatening at this time.

Bartelt say he doesn't know how many people watch local programming. He did say a recent Herndon High School game attracted 16 per cent of the system's subscribers. "It was going up against 11 channels during prime time," he said. "That's not doing too badly against that kind of competition.We are dealing with small interest groups.

One Reston resident - who keeps well informed on events in the community - summed up his viewing this way: "I watch cable three times a year - once for the Reston Birthday celebration at Lake Anne, once for a Herndon game, and once by mistake."