The Democratic National Committee seems to be at a loss to decide if fair is fair.

Three weeks ago, in a public briefing for state party leaders, top DNC staff members said they had just completed an exhaustive attitude survey that found middle-class voters viewing "fairness" as "a code word for giveaway."

Yesterday, DNC Chairman Paul G. Kirk Jr. told reporters, in effect, to disregard the previous statement.

He said the decision to talk publicly about the survey was "premature"; that the intepretation was "taken out of context"; that the fairness finding was based on material gleaned from small focus groups and was not supported by a subsequent poll, and that the notion that his party would abandon its commitment to the principle of fairness was "nonsense."

Kirk's statement illustrates a problem that Democratic leaders have encountered this year as they search for messages that will win back disaffected, middle-class white voters without alienating blacks, traditionally the party's most loyal voting bloc.

It also hints at staff problems at the DNC. Earlier this week, DNC executive director Brian Lunde announced that he was leaving as soon as Kirk could find a replacement. He and Kirk insisted yesterday that the decision was months in the making and had nothing to do with differences over the survey. However, several sources close to the DNC said Kirk thought Lunde and two subordinates had mishandled presentations of sensitive material.

The DNC's $200,000 voter attitude survey, the most exhaustive the party has undertaken, was fashioned in two parts. The first consisted of 43 focus-group sessions in six cities in which small groups of voters were interviewed in depth to probe for deep-seated attitudes and try to gauge their intensity. The second part was a 5,500-person nationwide poll.

Kirk said the word "fairness" was not used in the poll and never came up, not even in answers to open-ended poll questions.

Lunde, however, reiterated yesterday that the negative connotation of fairness among middle-class voters was "a very strong finding" of the focus-group sessions. He was supported by Milton Kotler, head of CRG Marketing of Washington, who wrote a lengthy analysis after conducting the sessions on a DNC contract.

"What Brian said about fairness accurately reflects the way white urban ethnics and southern middle-class whites view the word," Kotler said.

Kirk suggested yesterday that some of the confusion over fairness was purely semantic, "an eye-of-the-beholder thing." In 1982, when Democrats successfully used the fairness theme, it was part of a broader attack on the impact of President Reagan's economic policies, which they said favored the wealthy at the expense of the working class. But now, in better economic times, fairness apparently is not viewed the same way by middle-class voters. Part of the change may be related to racial attitudes, according to other research that the party has conducted this year.

Stanley B. Greenberg, a New Haven, Conn., pollster and consultant, questioned focus groups this spring -- before the DNC survey -- in Macomb County, Mich., a working class suburb of Detroit where Democratic voters have shifted extensively to the Republican column in the past several elections.

"These white Democratic defectors express a profound distaste for blacks, a sentiment that pervades almost everything they think about government and politics," Greenberg wrote in a report commissioned by the Michigan Democratic party and financed primarily by Michigan labor unions.

Pollsters caution that focus groups' findings can sometimes distort and overstate voter attitudes. Nevertheless, Democratic leaders nationwide briefed by Greenberg this year have said they were sobered and troubled by his findings.