When the Supreme Court ruled that public schools can conduct "reasonable" searches of students, many school officials thought the decision was on "our side" for a change but that it would have little impact on how schools are run.

The decision last week leaves unchanged a state law in Maryland and school board rules in the District that limit searches much more sharply than the court said the U.S. Constitution requires. In Virginia, where local school systems set such rules, officials said most school districts already follow the Supreme Court's standard.

In a 6-3 decision, the court said a search can be conducted in a school if there are "reasonable grounds" that it will turn up evidence that either laws or school rules have been broken. But the court added that the search itself must be "reasonably related" to the nature of the offense and not be "excessively intrusive."

Although schoolchildren have "legitimate expectations of privacy," the court said there is a "substantial" need for school discipline. In recent years, it said, "School disorder has often taken particularly ugly forms; drug use and violent crime in the schools have become major social problems."

"I very rarely have to do a search," said Frank Tracy, principal of High Point High School in Prince George's County. "But it's nice to know that the court is on our side.

"You must have order in the schools," Tracy continued. "This seems to be a way of the Supreme Court [saying] to principals and teachers , 'We support you. We want you to do a good job.' "

The president of High Point's Student Government Association, senior Virginia Smith, was much less pleased than Tracy with the court's decision. The case that produced the ruling arose from the search of a purse belonging to a 14-year-old New Jersey student, which turned up evidence that the girl possessed marijuana and was selling it to classmates.

"I don't like the idea that you can go into a student's private property," Smith said. "You can't do that to an adult [without a warrant]."

Smith added: "The drugs are bad. But you just have to weigh that danger against the students' rights. . . . I trust the administrators at High Point to do [a search] with discretion and in the right way. But I wouldn't trust the administration at a lot of other schools."

Under Maryland law, amended in 1982, a student can be searched if there is a "reasonable belief" that he or she has an item that it is a "criminal offense" to possess, such as a weapon or drugs. The search can be made only by a principal, an assistant principal or a school guard. It cannot be done by a teacher, as the Supreme Court allowed; and, according to a Maryland State Board of Education rule, a third person must be present during the search.

Ellen Heller, a deputy state attorney general who handles legal matters for the state education board, said the Maryland law means a search cannot be conducted just to enforce a school rule, such as a ban on smoking or spitballs, which the Supreme Court says is permissible.

"It appears that we're getting a better shake from the Maryland legislature than the Supreme Court," said John C. Roemer, executive director of the Maryland chapter of the American Civil Liberties Union. "It shows you the state civil liberties are coming to." The ACLU supported the student in the New Jersey case, who was identified in court papers only as T.L.O.

However, Roemer said, there seems to be little interest among students and parents in Maryland in trying to stop school searches. He said no one was willing to sue in two search incidents in the past year, despite contact with ACLU lawyers.

At Towson High School in Baltimore County, he said, members of a gym class that had gone to a roller rink were searched for marijuana after the scent of marijuana cigarettes was detected in a bathroom. In Carroll County, an entire high school football team was required to take Breathalyzer tests, he said, after a coach found a soda bottle on the team's bus that smelled of alcohol.

Roemer said that "most parents don't care about the Fourth Amendment," which forbids unreasonable search and seizure. "They want their kids searched and every kid searched if they think there are drugs around. . . .

"There's concern about safety, and I understand the concern," Roemer continued. "We say that there are things more important than stopping skulduggery and that one of them is protecting people from intrusion by government agents."

In the District, a school board rule, enacted in 1975 and amplified by a superintendent's directive last year, permits students to be searched only if there is "probable cause" that they possess something "illegal or harmful" that would interfere with school discipline -- a standard requiring much more certainty than the test of "reasonable suspicion" permitted by the Supreme Court. Under the D.C. regulation, no search can be made unless a principal gives prior written approval.

All these restrictions also apply to searches of school lockers, which the Supreme Court did not deal with in last week's decision. Most earlier lower court rulings have held lockers to be school property and thus subject to official control.

"The directive and rule are so stringent that we doubt if any [searches] are really going on," said D.C. school board attorney George Margolies.

David Splitt, the former school board attorney who drafted the rule, said searches were limited so severely "because the flow of public policy and court decisions was toward greater student rights. . . . We were trying to avoid a lot of lawsuits."

Edward A. Wynne, a professor at the University of Illinois who has written widely on student behavior, said many schools reacted "defensively" to court decisions in the late 1960s and early 1970s that expanded student rights to stage protests and limited the power of school authorities to suspend students or censor publications.

"There was a decline in the school's informal authority and a legalization of relationships," Wynne said. "The schools adjusted to a moderate level of disorder that would have been intolerable in the past." But, he said, the latest Supreme Court ruling "will send a signal to school people that they can operate in a common-sense fashion. We need more such signs, but this is helpful."

"For a while in the mid-70s, I think a lot of educators got terribly apprehensive," said Peter Blauvelt, chief of security services for the Prince George's County Schools. Blauvelt also is president of the National Alliance for Safe Schools, a nationwide group of school safety officials.

"Now I think we'll see administrators feeling more comfortable when they do what has to be done," Blauvelt added. "But I think this decision is pretty middle of the road. Students don't give up all their rights at the schoolhouse door. I think the court is still telling us, 'Be careful.' "