Due to an editing error, Democratic presidential nominee Walter F. Mondale's criticism of Vice President Bush's tax payments was mischaracterized in an article Thursday. The sentence should have read: "Mondale, in campaign appearances, has been criticizing Bush for paying about 13 percent of his income in taxes in 1983 . . . ."

Walter F. Mondale significantly improved his rating with voters by his performance in Sunday night's debate but did not immediately gain much ground on President Reagan, the latest Washington Post-ABC News poll indicates.

In a trial heat, Mondale, who a majority of viewers said won the debate, shaved three points from Reagan's 18-point pre-debate advantage. The Post-ABC poll completed Oct. 2 had given Reagan a 55-to-37 percent lead. The survey taken Monday and Tuesday nights gave the president a 56-to-41 percent lead.

But Mondale's personal rating with the voters improved dramatically, as a sizable majority rated him the winner of the debate. His favorable/unfavorable scores shifted from 41 to 49 percent before the debate to 54 to 43 percent after it, a net gain of 19 points.

Reagan's personal rating remains high, but the past week has seen a narrowing of the gap between the approval scores of Vice President Bush and his challenger, Rep. Geraldine A. Ferraro (D-N.Y.), who debate tonight in Philadelphia.

The three major networks will carry the debate beginning at 9 p.m. A transcript will be carried in the later editions of Friday's Washington Post.

Ferraro comes into that contest as the untried challenger against Bush, who was tested -- and bested -- by Reagan in a half-dozen debates during the 1980 Republican race for the Republican presidential nomination. But Democrats are hoping that a strong performance from the first female member of a major-party ticket will continue the momentum they appear to have gained from Sunday night's showdown between Reagan and Mondale in Louisville.

Six in 10 of those polled said they saw at least half the 100-minute confrontation, and 55 percent said Mondale won. Only 18 percent said they thought Reagan came out on top. The remainder thought it was even or had no opinion.

There was some comfort for the Republicans in the poll finding that Reagan's debate performance, which campaign officials have said was disappointing, did not immediately erode his public support. His favorable/unfavorable score was 60 to 35 percent before the debate and essentially unchanged, 61 to 36 percent, 48 hours after the debate.

But Mondale's gains were striking, particularly among male voters and independents. In both groups, he turned strongly negative ratings into a positive standing.

Perhaps aided by Mondale's coattails, favorable/unfavorable impressions of Ferraro climbed from a narrow 44 to 42 percent positive in the pre-debate poll to a 52 to 40 percent positive in the latest survey. During that time, during which there was extensive publicity about Bush's income tax payments, Bush dropped from 60 to 28 percent positive to 57 to 36 percent.

So they enter tonight's debate closer to parity than they have been since the start of the campaign.

The ultimate significance of last Sunday's debate remains clouded. Public opinion analysts believe that changes in attitudes often precede shifts in voting intentions, especially in a contest like the Reagan-Mondale race, where a high percentage of voters express a strong preference early in the campaign. Moving voters off their original choices is a complex process that takes more than a few days.

The gain in Mondale's ratings, for example, was much more marked in Tuesday's interviews than in Monday's, even though there was no increase in the percentage saying he won the debate.

The Post-ABC survey was based on call-backs to 1,035 people who had participated in an earlier September poll. That technique allows examination of shifts in attitudes among specific voters, and it contains some hints of what could become a pro-Mondale trend.

About one of every six of those polled a second time expressed a better opinion of Mondale after the debate. Among only those voters, Reagan's margin dropped from about a lead of about 2 to 1 to about 5 to 4. That shift was partially offset by Reagan gains among the 9 percent who said they thought worse of Mondale now. A lopsided majority of the first group had watched the debate; fewer in the second group had seen it.

Strategists and pollsters in the rival campaigns said the Post-ABC results were similar to their own post-debate findings, but they differed in their interpretations.

Edward J. Rollins, Reagan's campaign director, contended Mondale had been effective only in "getting the message to some wavering and undecided Democrats that it was time to come home. The anti-Reagan vote is about 44 or 45 percent," he said, "but because of his incredibly high negatives, Mondale hadn't even been getting that generic vote. As he deals with that problem, he improves his vote, but the president's support has not been hurt."

Robert G. Beckel, Mondale's campaign manager, said, "The movement seen in The Washington Post-ABC Poll is very similar to our own poll, which indicates one of the most dramatic shifts in attitude toward a presidential candidate after a debate since the Kennedy-Nixon debate of 1960.

"We expect a significant improvement in days ahead . . . ," he added.

Richard Wirthlin, Reagan's pollster, said his post-debate surveys found "virtually no erosion in Reagan's perceptual strengths. His high personal approval and job approval ratings are still in place."

Peter D. Hart, Mondale's pollster, said that by asking the question differently, focusing on "whether what you have seen this week makes you think better or worse" of Mondale and Reagan, he has [TEXT OMITTED FROM SOURCE]