JOSHUA P. STARR, tapped to be the new superintendent for Montgomery County Public Schools, says that he isn’t interested in making any “sweeping changes” to Maryland’s largest school system. That’s understandable, since Montgomery schools are considered among the best in the nation. But just as the man he is set to replace constantly raised the bar, we hope that Mr. Starr will be equally fearless in pushing the system to new highs.

The county Board of Education announced its selection of Mr. Starr last week to replace retiring Jerry D. Weast as head of the 144,000-student system, subject to final contract negotiations and approval by the state superintendent of schools. Mr. Starr, 41, superintendent of Stamford (Conn.) Public Schools, started as a special education teacher in New York City’s public schools, where he was later put in charge of school performance and accountability. Montgomery school board member Patricia O’Neill said that the board was impressed with his “enthusiasm, his research of us, his commitment to data-driven decision making and his youth.”

In moving to Montgomery, Mr. Starr is taking on a school system with 10 times more students than the one he has run for six years. Instead of having to worry about 20 schools, Mr. Starr will be responsible for 200. Size, though, may be the least of the challenges for a system dealing with rapidly changing demographics and tightening public resources.

Mr. Weast’s signature achievement was to address the disparity in education and achievement between white and minority students by raising expectations for everyone. He directed new resources to needy schools without alienating the more affluent parts of Montgomery, and he got results. Still, a gap persists. And unlike Mr. Weast, who had the advantage of prosperous times, Mr. Starr will have to maintain momentum with fewer resources. That might mean a changed calculus with a teachers union that cooperated with change in part because of generous compensation packages. He also will have to work out a relationship with a school board that simmered over its perception that Mr. Weast was too much his own man and paid it little heed.

Mr. Starr demonstrated in Stamford that he wouldn’t back down from positions he felt strongly about; in general, he showed that he was unwilling to be micromanaged. We confess to being disappointed by his objections to merit pay for individual teachers and his reservations about the need for charter schools in Montgomery. But we are encouraged by his accomplishments in a district with a challenging, diverse student population, particularly his use of data to standarize curriculum and hold teachers accountable. “He’s really been tested in the crucible here,” Susan Nabel, former president of the Stamford Board of Education, told the Gazette newspapers. That ought to serve Mr. Starr well in Montgomery.