Jimmy Carter and Ronald Reagan just may be wasting most of the $15 million each is spending to advertise himself on television this fall, if an experiment with nine independent, still undecided Wilmington voters is any indication.

Of course, this unscientific conclusion must be an exaggeration. The money can't really be wasted -- the candidates' TV commercials must be having some effect. But the evidence from this experiment is pretty strong. At least in this group of voters -- all quite serious, educated, middle-class Americans -- television commercials aren't overly persuasive.

Except, perhaps, for Barbara Hickey. She declared herself leaning toward John B. Anderson before viewing five Carter and five Reagan commercials. Afterwards she said she would be voting for Jimmy Carter, who had been her choice in 1976. "I just turned really off on Reagan, sitting here in this chair," she exclaimed, seemingly surprised at herself.

Oh yes, and Chinx Noyes. She's a museum guide, age 52, who voted for Carter in 1976 and said before seeing the commercials she was likely to vote for him again this year. When she saw a new Carter ad in which the president insists that nuclear arms control is the overriding issue of our time, her inclination became firmer. "That made me think -- whoops, I'm really scared of Reagan."

Television advertising is both the biggest and the least understood aspect of modern presidential campaigns. Both candidates will put more money into it than anything else this year, and a lot of that money surely will be wasted. But Barbara Hickey and Chinx Noyes may be examples of how TV advertising can have an effect -- their testimony can't be dismissed, even if it can't be clearly understood either.

The Washington Post found this sample of nine Delaware voters by telephoning nearly 200 registered independents here in search of people who were still undecided, and who would take a couple of hours out of their Saturday to watch Carter and Reagan commercials. Undecided independents were chosen because they are probably the single most important target of the candidates' television advertising, which is actually aimed at a tiny fraction of the electorate. The commercials were shown in the studio of WHYY, Channel 12, the educational channel here, which generously contributed its facilities and staff to make the experiment possible.

The commercials this group saw are currently being broadcast. They included a five-minute biography of Reagan emphasizing his accomplishments as governor of California, a five-minute Carter commercial in which the president speaks on the importance of nuclear arms control, and four 30- and 60-second spots for each candidate. Reagan's extol his record as governor (in one Gerald R. Ford does the extrolling) and attack rising prices in the Carter years. In the Carter spots, an announcer and Californian-on-the-street raise doubts about Reagan, and members of a steelworker's family in Birmingham explain why they like Carter.

Apart from Barbara Hickey (a 34-year old Welcome Wagan hostess, substitute teacher and mother) and Chinx Noyes, the seven other members of this group unanimously expressed disdain for the ads they saw. Here are some of their comments:

James M. Netzel, 32, a supervisor in the marketing division of E.I. Dupont, who is currently leaning weakly toward Reagan:

"There's nothing that they advertise about their attributes that makes me say, 'Yeah, that's the guy I want.' . . . . I'm glad he [Reagan] was in the military, and I'm glad he came from a family, and I'm glad he worked hard -- I think that's great, but that doesn't deal with the issues we're all concerned about -- energy, inflation, foreign policy, the whole schmeil . . . . These commercials really don't sway me one way or the other."

Mary Netzel, his wife, whom he thought would also say she was leaning slight toward Reagan, but actually declared herself still up in the air:

"Evidently, these people feel that these commercials are effective or they wouldn't continue making them, but I can't in my mind reconcile myself to the fact that they are worthwhile . . . Gosh, you worry that this kind of medium can really persuade a lot of people and it's just a bunch of bull. And you see it as a very manipulative medium . . . I don't see any relationship between what we see here [in the commercials] and what's going on [in the country and the world]."

Florence Twardowski, 38, mother of four, who "hasn't had a winner since [John F.] Kennedy" in a presidential election, wrote in Hubert Humphrey in 1976 and leans toward Anderson now:

"I don't like commercials at all. I know they're going to say the best possible thing they can say about each of them, and the most horrible things they can say about the other candidate. They don't do anything for me. I like to leave the room when they're on."

William (Lee) Little, 22, a graduate student at the University of Delaware who voted for Gerald Ford in 1976 and now leans to Anderson:

"They really don't affect my decision or alter my perception at at . . . just little parts in the ads really annoy me. Especially when Ronald Reagan said he served four years of active duty [in fact, an announcer's voice says this in the Reagan documentary], when his active duty was in Hollywood making movies -- what the hell, when I hear that type of stuff, well, that's a negative for Reagan."

These voters provided many reminders that the truly neutral, impressionable voter exists only in fiction, or perhaps in political science. Even undecided, registered independents have prejudices and predilections. Jim Forrest, a high school English teacher, was a good example. His first reaction to the commercials was that "most of Carter's commercials were attacking Reagan, whereas most of Reagan's were talking about his own record. I thought Carter seemed to be taking a more defensive position that way -- I think it makes him come out worse."

Later in the conversation Forrest acknowledged that "I don't want to vote for Reagan, but I think Carter's record is so terrible -- he's contradicted himself every month . . . and I think he's got the worst advisers they've ever had in Washington." Forrest voted for Carter in 1976.

Twardowski, who wrote in Humphrey rather than vote for Carter last time, also expressed visceral annoyance with the president. She reacted strongly against the opening of the five-minute Carter commercial, which begins with an announcer saying, "Ladies and gentlemen, from the White House, the president of the United States . . . ." Twardowski said:

"If I had been in the kitchen when that came on, I would have come rushing in [to her TV room] thinking something drastic had happened . . . it would have scared me."

"Isn't that the point of advertising," asked Hickey. "It would have gotten you in there."

"But I would have been furious at him anyway 'cuz it was a commercial," Twardowski replied. And yet, later, she observed that she liked the way the president looked in that commercial. "That was the best-looking Carter I've seen in ages," she said.

Just what people see and retain from television ads is a mystery, as Mary Netzel demonstrated at one point in the conversation. "The most secure that I felt -- or the most secure that I felt I was supposed to feel -- was when [former president] Ford came on [in a spot endorsing Reagan]. I thought that was very effective."

She was asked if she remembered what Ford had said.

"Oh, just how good Reagan is. Let's see, what did he say? He seemed so sincere . . ." She had to be reminded by others at the table that Ford had talked only about what a good governor of California Reagan had been.

Reagan's record as governor is the principal selling point of his television commercials. The ads appear to be saying that because he was effective in Sacramento and because California is such a big, important state, Reagan can now be trusted as a president. That line of argument, interestingly, scored no points in this group. Several of these voters questioned the relevance of Reagan's California experience. One said "we've already had a governor of Georgia in there, and look what happened."