DES MOINES, FEB. 5 -- Attorney Timothy McCarthy will declare himself uncommitted at Monday night's Democratic caucuses in hopes of sending a signal to Albany for New York Gov. Mario M. Cuomo (D) to enter the race.

Banker Dean Payton leans toward former Arizona governor Bruce Babbitt (D), the candidate of candidness, but might stand up for Sen. Paul Simon (D-Ill.), who says he's "not a neo-anything," simply because Payton thinks it important that the Iowa caucuses "send a strong signal for someone."

Housewife Carla Stephan is withholding a choice between Vice President Bush and Sen. Robert J. Dole (R-Kan.) because "they're both guilty of indulging their little grudges" and "I just don't know yet which is more guilty."

And 80-year-old Herman Lihs, "retired and tired," as he says, is "pretty much decided" on Bush, but won't know until he sees how severe the weather is Monday night whether he will go out to the caucus in Wapello.

These are four of four dozen undecided voters interviewed the past three nights by The Washington Post, a small fraction of the thousands of uncommitted Iowa voters whose final judgment clouds the prospects in both parties and makes the polls here so chancy.

It is not unusual for many caucus-goers to be undecided up to the moment they reach the church, home or office building where their neighborhood caucus is held -- or to change their mind during the course of the evening as the discussion and decision-making goes on.

"Uncommitted" won the Democratic race over Jimmy Carter and five others here in 1976. This year, unlike 12 years ago, there is no organized effort on either side to elect uncommitted delegates to the next rounds of county and district conventions. But campaigns still find scores of genuinely undecided voters in every evening's telephoning -- especially on the Democratic side.

The voters who are considered likely to attend Monday's caucuses and who remain uncommitted have been bombarded by mailings and phone calls from rival campaigns. As a result, they are quite different from undecided voters at the end of the general-election campaign. The latter often are the least interested and least informed citizens; the uncommitted caucus-goers may suffer from an overload of information that makes choice even harder.

Joan Clark, a 61-year-old retired Des Moines compensation administrator, said, "I read the paper cover to cover every day and all the material that comes in the mail. And I'm just not very happy with the choices."

Clark, a registered Republican but a self-described political independent, was "really disappointed" as she watched the Iran-contra hearings on television last summer, "and can't believe all these Republican candidates are saying Ollie North is a great hero."

"I even thought about switching and going to the Democratic caucus," she said. "I like some things about almost all of the Democrats, but I'm just not absolutely sure. It's not usually this hard for me to make up my mind."

Katie Schneider, 64, is finding it so hard to decide between Bush and Dole that she has decided to call the lawyer who sponsored her as an immigrant from Germany 30 years ago and ask his advice. "Bush is not straight," she said. "I don't trust him too much. But Dole, he's too much a politician, too. It's important we do what's right, but it's really hard to know."

Several undecided Republicans expressed sentiments like those of Marvin Slagg of Humeston, who said he had supported Bush in 1980 and was leaning in that direction until the question of the vice president's role in the Iran-contra affair came to the fore. "I just can't figure out about all this contra stuff," he said. "I can't decide whether what he {Bush} did was good or bad."

Although few in number, the interviews suggested Bush and Dole are hurting themselves -- and making it harder for undecided voters to embrace either of them -- with their sharp personal exchanges in recent days. Stephan, who used to be a teacher in Manchester, warned that "how they act the rest of the way will decide how I vote."

On the Democratic side, where most candidates are less well-known, the number of undecideds is even greater. It was far from rare to find people going into the last weekend who, like Leslie Lesuer, still had three candidates on their minds. Lesuer, 54, the sales manager for a Des Moines restaurant supply firm, is weighing Simon, Rep. Richard A. Gephardt (D-Mo.) and Massachusetts Gov. Michael S. Dukakis (D). "It's changing every day," he said. "All three are basically in tune with what we need to do, but it's hard to figure out who'd get it done."

The Republicans take a quick straw vote at their caucuses and report the results immediately, while the Democrats have a more complex system of separating by first preferences, then allowing people to regroup if any set of supporters is too small (below 15 percent of the total) to be "viable." That process encourages some well-informed uncommitteds to think about becoming "strategic voters."

Shirley Simbro of Des Moines said, "I think I'll support Paul Simon, although at my particular caucus there will be a lot of Jesse Jackson people. I love Jesse Jackson and I really am a supporter of the values {Jackson and Simon} support."

"I don't think either one would have a chance to be president," she continued, "but I want to raise the support for their values. . . . So I'll go to support Paul Simon, then move to Jackson, and then at the next level {the county convention} I'll switch to Michael Dukakis."

Joy Neal, a deputy in the motor vehicle registration office, saw all the Democrats at the Des Moines Register debate and has heard several of them individually. But it hasn't helped. "I really like Simon and Dukakis best," she said, "but Dick Gephardt has said some good things about the elderly. My mother is 94 and in a nursing home, so that's awfully important to me, but I think I'll probably end up with one of the other two."

McCarthy, 29, said he likes the uncommitted option because he would like to see Cuomo in the race. But Dean Payton, a 39-year-old banker, feels strongly that "it's important we do not send seven candidates out of here with an equal vote, or this whole effort will be a waste of time.

"If we just send it on to New Hampshire without a recommendation, and let the fight go on for months, we're cutting our own throats," Payton said. "And if Gary Hart comes out as the Iowa choice, or Pat Robertson on the Republican side, the parties will never let us be first again, because those are not electable candidates."

So Payton is prepared to support Babbitt but ready to switch to Simon if the senator has a lot of support. "I just feel we need to make a strong statement," he said.

Not all the rationalizations are that sophisticated. Mary Murphy, a church secretary, is not sure who she likes and feels no pressure to decide.

"I don't like all the hullabaloo beforehand," she said. "Everyone has called at every hour of the day and night, wanting to know what I'm going to do. They've been wanting to know for 12 months. Let them wait a few more days."

Staff writer Dan Balz contributed to this report.