BUSING to integrate the Los Angeles public schools appears to be dead, for this school year at least, with the NAACP's recent decision to withdraw a petition asking that busing there be continued. The civil rights groups evidently is not giving up, though. It still has a case pending against the Los Angeles school board asking that busing be resumed. on grounds that, intentionally or not, most Los Angeles schools will have a majority of Hispanics or blacks in contrast to a few that will have sizable numbers of whites when busing is completely stopped.

All this back-and-forth yields very little in the way of answers to the overriding question of how effective school busing is in improving educational opportunities for minority students and whether busing is worth the effort and turmoil that have accompanied it from the first court order. In fact, the end of busing in Los Angeles has come as the result of an old legal tangle that has little relevance anywhere else in the country. But even so, the controversy offers a current view of the central issues some two decades after busing became an issue, and it comes at a time when busing is being labeled a failure in many quarters.

The Los Angeles school board was able to do away with busing because of major change in California state law. Before a 1979 referendum, state law required desegregation whenever there were schools with mostly white students in a school district that also had schools with mostly black or Hispanic students. There was no need to prove that the schools with more whites had better facilities or better teachers or that the segregation was deliberate; on the basis of racial composition alone, a court could order busing for desegregation. The statewide referendum changed that. Now California law holds that the court must have evidence of intent to segregate students or deny minorities equal educational opportunities before ordering busing. The new law generally falls in line with the way the Supreme Court has viewed desegregation. The California law's proponents say it won't be defeated on federal constitutional grounds; nevertheless, the NAACP is challenging it on the grounds, that it eliminates busing as a remedy even if segregation is found to be in evidence.

Despite the NAACP's attack, there is a larger question involved in the Los Angeles case. Since the early days of busing, the question of whether segregation is intentional or not has haunted American courts, and to this day thee is no satisfactory answer. Without proof of intent to segregate, the courts have been leery of getting involved. In the southern cases, desegregation was seen as a necessary remedy for a past of officially proclaimed and enforced segregation. But elsewhere in the country, where the history was different, that line of reasoning faltered, leaving the courts looking for proof of some intent to segregate schools in a community. Under the original California law, the issue was settled by studying the ratios of the black-white-Hispanic population in schools. When the ratio tilted one way or another from school to school, the courts were obligated to order busing. Under the new law, a school in a neighborhood that inadvertently grows to be an ethnic bastion is not necessarily viewed as segregated, and the courts have no grounds on which to order busing.

The issue of school segregation has moved well beyond the original context: to ensure that all children, regardless of race, have the right to go to any public school they are eligible to attend. The real threat to children today is not so much official segregation as plain bad schools, especially in big cities where black students commonly make up more than three-quarters of the public school population. But where segregation is still the problem and can be measured by comparing the facilities, teachers and supplies in mostly white and mostly black schools, busing is often necessary medicine.