In an op-ed this month, “Time out on standardized testing,” Montgomery County Public Schools Superintendent Joshua P. Starr explained why he thinks there should be a moratorium on federally required standardized testing. I disagree.

I enter this conversation with some trepidation. Although I taught in Montgomery schools for one year, I have spent most of my life in Fairfax County, where I served as a school board member and a state legislator. But at least some of the lessons I learned on one side of the Potomac River apply equally to the other.

First, a little background. In the 1980s, Maryland was one of the first states to require students to pass a minimum competency test to receive a high school diploma. In the 1990s, the state developed the Maryland School Performance Assessment program (since replaced by the Maryland School Assessment), which provided student data to teachers and schools.

That history of accountability was central to the state’s receiving a waiver from some of the requirements of the No Child Left Behind Act. The promises of some relief from federal requirements were predicated, in part, on a commitment that evaluations of principals and teachers would consider actual student achievement. Now, Starr is balking at using student achievement data as any part of the evaluation system for teachers or principals.

Admittedly, student achievement in Montgomery County is still, on average, very high. But averages don’t tell you very much.

On average, 44.1 percent of MCPS students scored at the advanced level on the state’s elementary school reading exam. But while 60 percent of white students achieved that goal, only 27.4 percent of African American students did. In math, the numbers are roughly equivalent. While 45.8 percent of all students performed at the advanced level, just 24.3 percent of black students achieved that level, compared with 62.3 percent of white students.

According to a 2011 report by Maryland’s Higher Education Commission, in fiscal 2009 Montgomery College had the largest number of full-time equivalent students — 1,852 — in remedial education classes among Maryland community colleges. In other words, 11 percent of all Montgomery College students were paying tuition to relearn things they should have learned in high school.

Starr says he supports accountability. But from my side of the river, it looks like the only people who face any real consequences are the students.

My experience representing the diverse Mount Vernon area was that only the advent of national tests with real consequences led to sustained interest in our lowest-performing students.

While reasonable people can and do disagree about how much of a teacher’s evaluation should be based on student results, there is a growing consensus that these results should play some role. In the District’s IMPACT system, student test scores account for 35 percent of a teacher’s evaluation. In Orleans Parish, La., the figure is 50 percent. There’s no research yet to show that either of these is the “right” number; in fact, experts say, there may well be a range within which student scores might be properly applied to an overall evaluation.

Starr suggested that the transition to the Common Core State Standards will take time. He’s right, of course, but as Maryland noted in its waiver application, the state will be transitioning to the new curriculum a year before the assessments begin. The state has also agreed to field-test some of the assessments. So Maryland will probably be more ready for the transition than other states. And, as Kate Walsh, former Maryland State Board of Education member, points out, “Everyone’s scores are going to fall [in the first year]. It’s not like anyone will get an advantage.”

There’s a lesson to be learned from Tennessee, which recently raised the passing scores on its state assessments to more closely align them with the rigorous standards of the National Assessment for Educational Progress. Everyone knew scores would go down. But instead of trying to hide that fact, the state highlighted it. The education department launched a major public information campaign to tell residents that even though the scores were likely to show initial declines, the results would help educators make the changes needed to improve student performance.

That’s the approach Maryland should follow. State Superintendent Lillian Lowery, who supports including student performance in teacher evaluations, should stick to her position. It’s the right thing to do for students.

The writer, senior vice president for the think tank Education Sector, was a member of the Fairfax County School Board from 1991 to 2000 and chairman of the board from 1996 to 1998.