Prince George's County School Superintendent Iris T. Metts said yesterday that she wants to evaluate teachers and principals on student test scores and that she will fight to tie their compensation to student achievement.

Metts said she anticipates resistance from the unions representing teachers and principals but believes holding educators accountable for student achievement is critical to improving results. The 133,000-student school district ranks second-to-last in Maryland on average state exam scores.

"In the future, teachers will be evaluated on student achievement and test scores," Metts said during a meeting with Washington Post editors and reporters. "The unions will not be totally accepting of where we're going. We're going to have to negotiate. . . . We need a different attitude toward compensation."

Metts said that holding teachers, principals and administrators more accountable will restore public trust in the school system and bring more money to it from the county and state. She said her goal is for the system to see a six-point increase per year on average scores on the Maryland School Performance Assessment Program exams.

Metts's contract with the Prince George's school board, while providing an annual base salary of $160,000, also calls for thousands of dollars in bonuses if she produces results in a number of areas, including improving test scores.

Metts said she will appoint one of her new deputies, Frank Rishel, to help negotiate new contracts this fall with the unions that represent the system's 8,000 teachers and 185 principals and other administrators. Rishel is currently the deputy superintendent in Christina District in Newark, Del., where Metts once worked, but starts work in Prince George's Sept. 20.

And Metts said she will produce a study that will show that the system is spending far less money per pupil than most other school districts in Maryland, leaving the state open to a civil rights lawsuit from Prince George's residents.

"If we're looking to hold Prince George's accountable to the same standards but do not provide enough resources, that's accountability without equity," Metts said. "That's ripe for some court case."

Metts said that if she can restore the public's trust in the system, voters or a judge might overturn the county's property tax cap. County government leaders blame the voter-approved property cap--known as TRIM--as a major obstacle to funding schools.

"There's a perception in the community that the school system is not delivering," she said. "Until that concept is eliminated and there is a belief in the system, you will not have citizens in the county doing anything to increase taxes or repeal TRIM."

Metts said that in her prior job as Delaware's education secretary, she promoted a policy of tying teachers' and principals' salaries to their ability to improve students' test scores. The Delaware principals union agreed to such a deal, but the teachers union still is fighting it, Metts said.

Celeste Williams, head of the Prince George's teachers union, said her organization will not entertain such a proposal until teachers in the county have salaries comparable to those in other Washington area school districts and working conditions improve.

"You have to have the support and a good working environment," Williams said. "There's the real crisis here."

Metts, however, said teachers must make some concessions to help improve results. While scores on standardized tests are not always a perfect gauge of a teacher's ability, Metts said, they are a starting point.

"I'm well aware of the limitations of testing," she said. "But . . . all the other districts that started off with low scores have improved tremendously, and we've not had that progress. Either you can say we did not do the same instructionally or have a high degree of African American students or a high degree of students who live in poverty. But I say none of those are justifiable" excuses for not raising scores.

CAPTION: New Prince George's School Superintendent Iris T. Metts said teachers and principals must be held accountable.

CAPTION: Iris T. Metts said her proposal would build public confidence in schools.