A proposal to place 750 of Howard County's 25,000 students in special "center schools" for the gifted was sharply attacked tonight by school board members who said that the admissions standards for the program were too selective.

At the same time, all five members of the Board of Education called for an overhaul of the county's classes for gifted youths, attended by an estimated 4,500 students.

Board member William T. Manning questioned school officials about a proposal to limit admissions at center schools to those students scoring in the 99th percentile of standardized achievement tests.

"If the cutoff is the 99th percentile, what's going to happen with the 97th and 98th percentile?" asked Manning. "The one who scores in the 99th percentile will make it to a center school. Will the student who scores 98.5 miss the center-school bus?"

John A. Soles, Howard's curriculum director and a member of a committee that earlier this year proposed creation of eight center schools, said that the 99th-percentile rule "was never meant to be a firm number," adding that, "We will try to work with those students " who fall below the admissions standard.

Fewer than 800 students, or about 3 percent of Howard's entire enrollment, rank in the 99th percentile, school officials said. Ten percent of the students from pre-school to high school rank in the 97th percentile or above.

More than 50 county residents, many of them parents of gifted students, attended tonight's board meeting on the center schools concept that, if adopted by the board later this year, would be the first of its kind in the state, according to the state Education Department.

A handful of jurisdictions, including Montgomery, Frederick and Baltimore counties, have established schools exclusively for gifted students but none has set up center schools for elementary, middle and high-school grades, as proposed in the Howard plan.

Several board members criticized the center schools proposal as too vague, and the board directed Soles to draft a detailed report on the programs that these schools would offer.

"We don't have sufficient clarity in this proposal," said board member Stan J. Salett. He said that the current proposal "is like building a bridge between two clouds."