Beginning this school year, all students must pass the MCAS in those subjects in order to graduate from high school. Students have five chances, beginning in 10th grade, to pass.

Lawyers are seeking class-action status for the case and are challenging the use of the MCAS tests as a graduation requirement.

The suit lists six subgroups of students that it says have been disproportionately affected by the exams: African-Americans; Hispanics; students with limited English proficiency; students with disabilities; students attending vocational and technical education schools; and students attending schools in the Holyoke school district.

The suit contends that while a major education reform act adopted by the Massachusetts legislature in 1993 called for state assessments as a tool to evaluate schools and districts, state education officials "exceeded their authority" when, in 2000, they required students to pass MCAS exams to graduate.

"The flawed and illegal use of the MCAS exam as a graduation requirement has caused untold damage to students throughout Massachusetts," lawyers argue in the complaint.

"Scores of students have dropped out of school after failing the MCAS exam," it continues, "while many others have dropped out to avoid taking the MCAS exam. ... All of these students have been improperly and unfairly stigmatized through their inability to pass this fundamentally flawed test."

Tom Frongillo, a lawyer with the Boston-based firm of Testa, Hurwitz, & Thibeault, one of the law firms representing plaintiffs in the case, said that while state education leaders have used the exams to identify some 250 low-performing schools, it's students who are punished by a high-stakes tests.

"The MCAS exam is unconstitutional and violates Massachusetts' education reform act," Mr. Frongillo said. "We're attacking the validity of the exam."

Heidi Perlman, a spokeswoman for the Massachusetts Department of Education, said the legal challenge would not deter the state's efforts to improve student achievement.

"We stand by education reform, we stand by the [state] curriculum frameworks, and we stand by the MCAS exam," she said.

Eduardo Carballo, the superintendent of the 7,200-student Holyoke school system, expressed surprise, meanwhile, that his district was named in the suit.

"The state mandates the MCAS, and we have no choice but to follow it," he said. "We have a hard time understanding how we fit into this lawsuit."

Holyoke, a predominantly Hispanic district 90 miles west of Boston with many students from low-income families, ranks at the bottom when it comes to MCAS performance around the state. "We don't know if the reason they are picking on us is because we're the poorest district or we have the lowest MCAS ranking," Mr. Carballo added.

Results Improving

State education officials and business leaders defend the MCAS as a crucial part of raising standards and expectations for all students. But the high-stakes nature of the assessment has been a frequent target of criticism by many educators and activists in the state, who see it as a one-size-fits all approach to accountability.

State leaders point to significant gains in MCAS performance as proof that the goals of the exam are within reach of students. On the 2002 exams, a record 86 percent of 10th graders passed the English test and 75 percent the math test on their first attempts.

But some 12,000 students in the 64,000-member class of 2003, a large number of them African- American or Hispanic, have still not passed the exam.

About 44 percent of the African-Americans in the class of 2003 have not yet passed the MCAS, and half the Hispanic seniors have yet to pass. Students can take re-tests in December and May. If they continue to fail the tests, they can attend preparatory programs in the summer and take the MCAS again in August.

Regardless of how the case turns out, some MCAS advocates think it will help clarify the goals of the state's accountability system and help advance a much-needed conversation about ways to improve student learning and teacher preparation.

"Everyone knew [the lawsuit] was coming, and it will provide some helpful clarification on some key issues," said S. Paul Reville, a Harvard professor who helped shape the MCAS system and now chairs the Massachusetts Education Reform Review Commission, which monitors the state's implementation of the state's 1993 Education Reform Act.

Differing Opinions

Mr. Reville views most of the arguments in the lawsuit as weak, but he agrees that the state needs to do more to train teachers and make sure all students are given an opportunity to learn.

"It's a very significant case," he said, adding that "the question will revolve around what the remedy will be."

William Guenther, the president of Mass Insight Education, a Boston-based nonprofit group that works to improve student achievement, said he's confident that the exam will pass the legal test: "Based on all prior case law in Texas and elsewhere, we think the testing program will be judged valid."

In Texas, a federal judge ruled two years ago that a mandatory state graduation exam did "adversely affect minorities in significant numbers. The ruling added, however, that the test was not discriminatory and helped identify struggling students for extra attention. ("Federal Judge Rules That Texas Exit Exam Is Constitutional," Jan.19, 2000.)

"If the court can help identify individuals who aren't being served adequately and help direct resources to them, then we have all won," Mr. Guenther said. "But that doesn't warrant overturning the whole system."

That reasoning doesn't convince Jonathan King, a professor of biology at the Massachusetts Institute of Technology and a member of a statewide group called the Coalition for Authentic Reform in Education, which hopes to end the MCAS graduation requirement.

"The exam very much narrows the curriculum," said Mr. King, who has children in the Cambridge public schools. "You can't capture real skills. These kids have been in school for 12 years and have learned an enormous range of skills.

The MCAS is totally insensitive to the history and trajectory of the student," he said. "It tests the ability to take tests."

Learn more about the MCAS, from the Massachusetts Department of Education, including 2002 test results.