For five years, the back-to-school edition of Prince George's Extra has signaled the resumption of Homeroom, a forum in which readers and I have discussed all kinds of issues related to education, from lead in school drinking fountains to reading research, from Advanced Placement classes to No Child Left Behind.

Today, however, marks not a resumption but an end. I have taken a job with the Education Trust, an educational advocacy organization based in the District, so this is my last Homeroom column.

I write those words with a pang. I will miss Homeroom and will miss all of you. Through the years I have received many letters from you -- some agreeing with me, some disagreeing, but collectively displaying a deep understanding that education is at the vital core of the community. I will miss your passion.

Before taking my leave, I want to make sure all of you know how to arm yourselves with information about your schools and school system. It used to be that parents were supposed to send their children to school, and taxpayers were to pay for the schools, without ever knowing what the children were learning or whether the money was well spent.

But now parents, students and others have access to huge amounts of information about the quality of their schools. In part we can thank the federal No Child Left Behind law for this treasure-trove. But the Maryland Department of Education has done a better job than many states of making test results and other information accessible on two Web sites, www.mdreportcard.org and www.mdk12.org.

Anyone interested in knowing about the kind of job the schools are doing should explore those Web sites and then use that information to spark intense and informed discussions in every school and throughout the county.

For example: By looking at www.mdreportcard.org, one can see that Prince George's had much to celebrate with the publication of the third-grade reading scores on the Maryland School Assessments given to students in the spring. In one year, the percentage of students who met state standards increased by about 15 points. Last year, 39.4 percent of county third-graders read at the proficient or advanced levels. This year, the percentage jumped to 55.3. That is significant improvement, and represents the hard work and thoughtfulness of a lot of teachers, students and parents.

The results look a bit different when broken down by subgroups. For example, white and Asian students fared better on state tests than African American and Hispanic students: 75.3 percent of non-Hispanic white third-graders in the county met state standards and 78.5 percent of Asian children did so, compared with 53.2 percent of African American and 51.4 percent of Hispanic students.

That kind of gap in achievement is not much different from most places in the country, although it is still discouraging. But if you keep wandering around on the Maryland Report Card Web site, it is possible to find schools in Prince George's that do not have such gaps. Take, for example, Heather Hills Elementary School, where 87.5 percent of African American third-grade students met or exceeded state standards in reading, and 85 percent of white students did.

It is worth studying what Heather Hills is doing to propel so many more of its students toward success, to see what can be replicated elsewhere.

I have no answers as to why Heather Hills has been so successful, but one clue might be found in the statistics on the teaching force, found on the same Web site. During the 2003-04 school year, all its teachers were certified; it had no conditionally certified teachers.

Conditional certification is given to teachers who have not met the requirements to teach in Maryland. Some conditionally certified teachers are certified in other states and simply have to meet Maryland's particular requirements, but most are new to teaching and haven't yet completed their training. That doesn't mean they're bad teachers, but they are inexperienced and cannot be presumed to be expert.

Prince George's has been very good at recruiting new teachers and very bad at retaining them. Overall, one in five teachers in Prince George's is conditionally certified. In my opinion and the opinion of many observers, the lack of a stable and expert teaching force has been one of the reasons why many county students have not achieved at high levels.

If it turns out that the teacher certification rate at Heather Hills is a significant factor in its student test results, that finding should provoke much discussion among PTA members, politicians and civic leaders, centering on this question: What can Prince George's do to attract and retain an expert teaching force so that all schools can achieve at the level of Heather Hills?

Don't think that kids don't notice and care about this issue. One of my regrets in leaving Homeroom is that I haven't written enough about how serious today's students are about education. I'm not just talking about the kids who take all honors classes in high school and apply to highly selective colleges. Everyone knows they are serious. I'm talking about the other kids, the ones who struggle and may even pretend to their friends or their teachers that they don't care. They may not always be clear about their goals, but they know they need a good education or else they may face a lifetime of poverty and dependence.

A while ago I spoke to a classroom of Prince George's high school students, most of them seniors and juniors. They were not the academic stars of the school. I asked the kids what would have made school better for them. The vehemence of their answer surprised even me. "More certified teachers," they said, many of them in unison, quite a few lifting their heads from their desks to answer.

It seems little enough to ask. But to make it happen will take the concerted efforts of the entire county, and even the state and country.

As a citizen I will work to try to make that happen, but as a columnist I am saying goodbye. Thanks for letting me spout off. I'll miss you all.

Karin Chenoweth can be reached at homeroom@washpost.com until Aug. 31.