Behind the heated disputes over busing to desegregate public schools, another, and maybe more far-reaching, fight has been going on in the federal bureaucracy.

It involves the Department of Health, Education and Welfares ability to collect up-to-date statistics on the extent of school desegregation. Although now partially resolved, the fight has resulted in the blunting of HEW's basic tool fo enforcing civil rights law compliance.

The most current, detailed statistical material on the extent of school desegregation on a district-by-district basis is 4 years old - data from 1974.

David Tatel, director of HEW's Office for Civil RIghts, agreed that "there is no way we can make intelligent decisions on compliance targets" without recent data from OCR school surveys.But, he argued, a major task of the Carter administration's appointees at OCR has been "cleaning up the problems that were left behind" by the Ford and Nixon administrations, which downplayed enforcement of desegregation.

Material collected by OCR for 1976 remains undeciphered and is gathering dust in teh files. No survey was carried out for the just-ended school year. Moreover, next year's statitics will provide only a partial picture of the school desegregation situation, another result of the bitter skirmishing over data collection.

The paradox of the enforcement office working from 4-year-old data, even in the era of computers and quick processing techniques, stems from the political upheaval stirred by OCR's school surveys.

"We think that is outrageous," said Phyllis McClure, of the NAACP Legal Defense and Education Fund's office in Washington. "The purpose of the survey is to identify targets for compliance reviews. If there is a lag, OCR's productivity in compliance actions is delayed . . . It takes them far too long to process the data." McClure said.

Even if OCR had current data on hand, Tatel suggested, it might have to put other matters first. "We were left with a terrible reputation on the surveys. We were left with lawsuits - OCR's operations were taken over by the courts. Most of what we do is under court order. So a lot of what we are trying to do is rebuild - and our survey is just one thing. It will take us a couple years to catch up," he said.

OCR's new survey, redesigned and shortened by order of HEW Secretary Joseph A. Califano Jr., for the 1978-1979 school year was sent to school districts last winter. It is due here in October, but results and analysis will not be ready until a year from now.

Tatel said that would provide adequate time to allow OCR to pick compliance targets for the 1979-1980 school year. The NAAC's McClure said she doubted OCR could meet such a timetable.

"They need to analyze the material more promptly so they can put it into their annual operating budget," she said. "If the material is not ready to tell them how to distribute their resources, it will be too late."

OCR's problems with its survey go back to the early 1970s. School administrators complained bitterly that the surveys were too long and time-consuming. Congressional efforts were made to curtail the survey, which came to symbolize the push for the use of buses to achieve more desegregation.

The surveys began in 1966, as a way of determining which of the nation's 16,000 school districts were in compliance with civil rights laws. In time, as more information was sought, the surveys gew in size - apace with the protests.

By 1970 HEW was sending the forms to fewer districts, and every other year instead of annually. The 1975 and 1977 surveys were canceled, in part because of congressional and public protests over supposed intrusions on school administrators' time.

Among the critics of the survey, on the grounds that it was duplicative and burdensome, were the Council of Chief State School Officers, school principals' and school board organizations.

A chief defender of the survey was the Children's Defense Fund, which last year produced a long study of the problems in data collection to determine the extent of discrimination on account of race and sex.

The fund report said, among other things, that one point could not be denied: Without up-to-date indormation, civil rights laws cannot be enforced.