Among the many lessons education writer Karin Chenoweth learned about the fragility of educational success, one of the most powerful came from teachers at a Miami school that had made big gains in achievement for impoverished children.

“Classrooms were buzzing hives of reading, writing and academic conversation,” she writes in her new book “Districts That Succeed: Breaking the Correlation Between Race, Poverty and Achievement.” When she asked the teachers how long it would take for a bad principal to tear the school apart, she expected them to say they wouldn’t let that happen.

Instead, they frowned in despair and said about 20 minutes.

They knew about idiotic principals. Such people had the power to quickly kill the culture of trust, coherent decisions and thoughtful communication that had brought success.

Chenoweth’s book focuses on districts that have students from low-income families making significant gains in achievement. But she also tells stories of how swiftly good situations can fall apart. Chenoweth reminded me, optimistic by nature, how vulnerable even the best schools are to ill-considered changes of management.

In an earlier book, Chenoweth wrote about M. Hall Stanton Elementary School in North Philadelphia. A great principal had raised its achievement level from one of the lowest in the city to about average for Pennsylvania, a remarkable change. Then the principal took a job in D.C. to be near her daughter and grandchildren. She recommended three excellent administrators already working at the school as possible replacements.

Instead the district chose an administrator from a nearby school who immediately dismantled the systems that had been working. The urge to impose one’s own views is hard for some new bosses to resist.

“Gone were the regular data meetings, the student support teams, and the professional development based on individual teacher needs aligned to school goals,” Chenoweth said. “Gone was the collaboration and the firm but respectful treatment of students and teachers. Many of the staff fled, easily finding jobs elsewhere.”

Achievement dropped. Student misbehavior increased. After a few years, the district closed the school.

I have always been more interested in what teachers are doing in classrooms than how district superintendents are using their time in their big offices. Chenoweth suggests I am missing something. Weak and unfocused district leaders can do great harm, she said.

Chenoweth has been the writer-in-residence at the Education Trust advocacy organization since 2004. She found a superintendent in an Alabama district with 18 schools who never managed to visit the only three schools that served African-American children. Another superintendent never visited the only one of his district’s many majority low-income schools that had been recognized by the state for high achievement.

“Districts will often assign their newest and least experienced principals to their highest-need schools, which is basically a recipe for disaster,” Chenoweth said. “Even if the principal is ready to take on the challenge — a big if — they don’t have the connections and influence their more experienced colleagues do. And so, they often get last dibs on teacher candidates and are saddled with the teachers and staff members their more connected principals have eased out of their schools.”

Doubt runs deep about even the most solid proof of improvement in schools, particularly in high-poverty places nobody has heard of. Chenoweth said teachers and principals who worked hard to improve the Lane district in Oklahoma were overjoyed when it finally got an A on the state’s accountability scorecard. But people in neighboring districts suggested the school faked its results. When the Lane administrators explained in detail what they had done, the reaction was disappointment that it wasn’t a quick fix.

Toward the end of the book, Chenoweth argues we journalists may be part of the problem. Chicago newspapers were full of skilled reporters who failed to see much news in that district’s recent gains. A Stanford University team provided data on student achievement and socioeconomic standing in U.S. districts. The analysis showed that while a Chicago cohort of third-graders was well below the national average in reading, when they reached eighth grade they were at about the national average. The Stanford team found that no other large or even medium-sized district was able to grow student achievement by that much. Chenoweth’s reporting revealed this to be the result of significant changes in the ways Chicago children were taught, but the story did not catch fire in the local press.

“Part of the answer lies in the fact that reporters are by their nature skeptical,” Chenoweth said. One told the Stanford study leader she didn’t believe his numbers because they were at odds with the strikes, malfeasance and underfunding in the school system that Chicago papers did cover. “Reporters also reflexively react against the kind of boosterism typical of mayors and superintendents,” Chenoweth said.

During the pandemic, American parents got a clearer view of what makes schools work. Engagement by teachers with students in some districts and charter networks left a good impression, but nationwide many parents were unhappy.

That is likely to strengthen the overall skepticism about any claimed improvements. Thankfully, there are enough teachers and principals like the ones Chenoweth found to keep alive hope for impoverished children. Her book is a beacon for optimists, no matter how few of us there may be.