Dawn Brough, a dental laboratory office manager in Pepperell, Mass., has four children. They grew up knowing that "dropping out of school was not an option under our roof," she says. But for her youngest child Matt, that family commitment to getting a diploma is turning into a source of deep irritation.

Matt, a senior at Nashoba Valley Technical High School in Westford, Mass., has a learning disability. His mother says it affects math computation, calculation and application and also includes "verbal abstract and inferential reasoning, verbal concept formation, comprehension, organizational abilities and social insight."

Nonetheless, he has the makings of a fine electrician. One of his electrical teachers told his mother he was one of the top students in his class. Last year, he began working as a helper for an electrical company, an honor afforded only those Nashoba Valley Tech students who keep their grades up.

But in order to graduate from high school this year, he has to pass the Massachusetts Comprehensive Assessment System tests in math and English. They are called the MCAS (pronounced Em-cas). He has had four shots at them so far, but just missed the 220 passing score. His English scores have been 212, 216, 218 and 218. His math scores were 210, 212, 216 and 216.

I am grateful to Brough and her son for letting me tell their story in such detail. Whether or not students like Matt get their high school diplomas, or find alternatives that allow them to pursue their life goals, will likely determine the success or failure of our latest national effort to save the large number of children who have not been well-served by our public schools.

There is no question that the effort so far has had some success. In most states, and most importantly in our poorest neighborhoods, average test scores are up and educators are working harder than ever to make sure students acquire the knowledge and skills that will give them good choices after they graduate. Many schools have lengthened their day, brought in extra tutors, expanded summer sessions and carefully monitored individual progress to make sure every child meets the new learning standards set by the states, with the federal government's backing.

But we are entering a difficult period, one that the educators and politicians who designed this system have long feared. The new federal No Child Left Behind Act does not require that students pass standardized tests in order to graduate from high school, but several states have imposed that rule to motivate students and assure that their diplomas are valid proof of ability to deal with words and numbers.

New York has already begun to require high schoolers to pass the tests for their diplomas. Massachusetts will do the same this year. Virginia joins that group next year. Eventually more than half the states are scheduled to use tests to decide who will get to wave proudly that proof of graduation from the stage of the school auditorium.

The tests do not appear to be that difficult. In Massachusetts, for instance, 91 percent of high school seniors have already passed the MCAS. I would like my own children to be able to pass these tests. But the educators and policymakers know that if too many good, hard-working kids like Matt are denied their diplomas, mothers and fathers will start picketing their state legislatures and the test requirements for graduation will disappear. That, in turn, may lead states to water down standards and let young people graduate without the skills they need to have productive lives.

Many states, in order to avoid that political clash, have provided ways for students like Matt to get around the tests. In Massachusetts, a student may submit a representative portfolio of classwork selected by his teachers to show that he has mastered his lessons, even if he missed the MCAS passing mark. Brough tried to arrange that for Matt, but Judith L. Klimkiewicz, the school superintendent, said the portfolio policy was new and the district has not had a chance to collect anything for Matt to show.

Matt has another shot at the test in May. "I think he's going to pass," Klimkiewicz said. Joan O'Brien, a former tutoring center owner who is chair of the local school committee (the Massachusetts term for school board), is helping Matt and other students prepare. Parents from all over the country tell me that their children with learning disabilities very much want to pass these tests. Thankfully, most American teenagers still consider a high school diploma worth working for. One mother in Jefferson County, Ala., told me her son, who has autism and paranoid schizophrenia, has taken the Alabama test for his diploma 14 times and gotten as high as a 66 -- passing is 68.

I would like to hear more stories of students with disabilities who are struggling to pass these tests and fear the consequences of not getting a diploma. The more I looked into Matt's situation, the less likely it seemed he would be hurt much by failing the MCAS, but every state and every student is different.

Even if he does not pass the standardized tests, Matt will be able to don a cap and gown and participate in graduation with his classmates. After the ceremony, they will receive their diplomas in the cafeteria. Instead of a diploma, Matt will get a Certificate of Attainment -- proof that he had passed his courses, if not the MCAS. He has told his friends what is happening, but he could have kept it to himself and no one would ever have known that he wasn't getting the same piece of paper.

But Matt is still angry about this. "I worked so hard for 12 years and then they come up with a test I can't pass," he said. He plans to keep taking the test, because he thinks he needs a diploma to get the electrician's license that is his number one goal. There may be a program at a local community college to help him prepare for the tests. Brough said she has even considered sending him to a high school across the nearby New Hampshire border and getting a diploma there, since New Hampshire doesn't require that students pass a state test.

Klimkiewicz, a veteran vocational education administrator, said she thinks the state will allow students like Matt to get their license just with the certificate he will receive if he doesn't pass the MCAS. Very few community colleges require that students have high school diplomas. Matt and his mother thought the certificate would not be enough to join the military, but an army recruiter in their area told me they are wrong.

That leaves the concern among many parents have that the tests are messing with their children's self-confidence. "To make things worse for their self-esteem," Brough said, "you should hear the jubilant radio commercial that is out there. It says how the MCAS is working and the kids are just loving the challenge!"

There is, however, something in the way that Brough talks about the situation that sends another message to the governors, legislators and state school board members who set up these tests. They hoped parents like Brough whose children could not pass reading, writing and math tests like the MCAS would begin to wonder if their schools were doing their jobs.

That is exactly what Dawn Brough is wondering these days. "There are things on this test he was never exposed to even though the teacher knew what they needed to teach him for this test," she said. "I'm not asking much, just teach him what he needs to know to receive a diploma, and comply with important requests such as turning in my son's work samples. It's not that hard to do."