Down in the MGM Grand hotel's shopping arcade, just past the food court and the Forever Grand wedding chapel, a stranger stops me with a proposition. This happens all the time in this town, I know, but in this case the offer is really unusual:

"Would you like to register your opinion about a new television show?" asks a tall, friendly man, whose name is Zachary Werner.

Actually, I did want to get a few things off my chest about "Joe Millionaire" and "The Bachelorette," but Werner doesn't seem too interested in that. Instead, he explains that he wants me to be part of a test panel that would watch and comment on an as-yet-unseen show. It doesn't sound too tough to me.

As it happens, Werner is a "host-moderator" at CBS Television City, located along the MGM Grand arcade. Television City looks like nothing so much as a souvenir shop ("Everybody Loves Raymond" coffee mugs, "Osbournes" T-shirts), but there's more to it than that. It also happens to be one of the nation's busiest audience test facilities, a place where networks come in their continuing quest to make TV shows just a little more entertaining, or at least a little more popular.

Morning till dinnertime, 365 days a year, Werner and his TV City colleagues herd tourists strolling along the arcade into four conference rooms adjacent to the souvenir shop. Their mission: to find out what Middle America wants to watch next, so network executives don't have to figure it out for themselves. Last year, some 66,000 people sat down at TV City to offer detailed reactions to programs being considered by CBS and its Viacom-owned brethren, UPN, MTV and Nickelodeon. Other cable networks, such as Lifetime and Discovery, check in, too.

NBC does its testing at not one but two Vegas facilities, in the Venetian hotel and the shopping mall at the Aladdin, both on the Strip. It seems Las Vegas, with its 36 million annual visitors, is the perfect demographic crossroads of the TV Nation, America's new Peoria.

I soon find myself shuffling into a room that looks like the new-media lab of a particularly well-funded high school. There are rows of desks and comfortable office chairs, and banks of computers with odd-looking knobs attached to them. There's a huge TV set at one end of the room, and an empty feeling in the air. Maybe that's because it's just past 10 a.m., and Werner was able to rustle up only me and a couple from Chicago, Joe and Gloria Pacheco, from the nearly deserted arcade.

Werner explains that the computer will ask us a few questions about ourselves, and then we'll watch TV. In fact, it's more than a few questions. Prompted by the computer screen, we're soon volunteering lots of personal information -- education, income level, age, TV viewing habits, etc. It's frankly more than I want anyone to know about me, especially a computer in Las Vegas.

Then Werner explains the purpose of those funny knobs. This is our own "real-time" rating system. Twisting the knob all the way to the right, up to the 100 setting, means the viewer is enthralled by what he's seeing. A middle setting registers indifference, or merely neutrality. A leftward twist down to zero means, roughly, that you'd rather be losing your rent money in the casino upstairs. Our second-by-second reactions will be recorded, Werner says.

Finally, it's showtime. The big TV flickers on, and a show called "Get Packing" begins. It's a little hard to figure out at first, but eventually we learn that "Get Packing" is a sort of reality game show.

The program pits two young men against each other for the opportunity to win a vacation with an attractive young female contestant. The guys have 10 minutes each to rifle through the woman's apartment to determine her taste in shoes, clothes, food, even underwear. Then each man gets $1,000 to go shopping for items he thinks will appeal to her. The woman selects her date based on the items each contestant has packed in a suitcase.

From what I can tell, "Get Packing" seems to be trying to combine features of several popular "reality" shows -- the consumerism of "Trading Spaces," the romantic competition of "The Bachelor," the vandalism and home-invasion segments of "Cops."

I quickly grow impatient with the show's hyper-chipper tone and inane premise. I turn my knob hard left, hoping that the computer will register a permanent flatline of pique.

Then I imagine that this will only brand me as a crank. I fear my opinion will be dismissed as aberrant, and thus unworthy. So I start twisting madly, more in boredom than anger. I know this is probably messing up TV City's carefully calibrated scientific research, but I can't help it.

Occasionally I look over at the Pachecos, who are sitting in the back row with me. When a male contestant on "Get Packing" inspects the contents of a woman's underwear drawer, the couple look baffled. Gloria Pacheco sighs.

It's never clear during our screening which network plans to air "Get Packing." Television City employees aren't supposed to say, lest it taint the research data or perhaps embarrass the network's executives.

But it soon becomes evident that the program is the work of the Travel Channel, a cable network owned by Bethesda's Discovery Communications. Super sleuths could deduce this from the way questions are worded on the post-screening survey, which all but ask, "Would you watch 'Get Packing' on the Travel Channel?"

Several days after the screening, long after we've filled out another questionnaire that registers our thoughts about virtually every aspect of "Get Packing," I call the Travel Channel to ask what they'll make of all this.

The news is a little disappointing. Steve Cheskin, the channel's general manager, patiently explains that the show is already scheduled to start airing sometime this summer, which means my knob work won't kill it. But, says Cheskin, our feedback will help the show's producers "fine-tune" elements of the series.

Such as? "We're always looking for trends in the responses," he says, "when a number of people say the same thing over and over." For example, Cheskin says test audiences once found that the host of another Travel Channel show was making too many jokes, which distracted from his "credibility." In which case, "we told him to tone it down."

Cheskin mentions that we might play one crucial role in shaping "Get Packing." In the pilot we saw, there were two variations of the game -- one in which the men meet the female contestant beforehand, another in which the contestants meet only after the woman had selected a suitcase. "We want to find out which version people like most," Cheskin says.

I don't recall being offered a selection marked "neither."

All of which makes you wonder: With all this fine-tuning, all this examining of the nationally representative viewer psyche, why aren't more TV shows better? Is it possible that the process can actually make TV worse, given that it exposes every creative choice to a popularity contest? And won't viewers always vote for the acceptable and familiar until they're offered something bold and new and original?

CBS's head of research, David Poltrack, the man in charge of Television City, says that testing can't make writers more creative or turn every actor into an Emmy winner. What it can do, he says, is offer predictability. He points out that no series aired on CBS over the past 20 years ever attracted more viewers than test marketing predicted it would. Knowing how a show is going to pan out is a good thing, Poltrack says. And besides, with billions of dollars at stake, taking wild guesses is out of the question.

As the Pachecos and I sauntered out of the conference room, Werner handed each of us an envelope. Inside were coupons for a 10 percent discount at the souvenir shop and tokens for games at the hotel amusement center. It was a small measure of thanks, I guess, from a grateful network.

Gloria Pacheco certainly wasn't complaining. On the other hand, she did say, "I wish the TV show was better."

Bill Smith works behind the scenes at the polling facility, located in a network souvenir shop in the MGM Grand Hotel.Host-moderator Lisa Salzman directs "audience" members about to evaluate new TV shows at CBS Television City, where last year 66,000 people took part in such surveys. Left, Beth and Brian Omg offer their responses via computer.