Like many other parents, Lisa B. Donlan was cautiously optimistic back in 2002 when Joel I. Klein, a former federal prosecutor andBertelsmann executive, was appointed chancellor of the New York City public school system. Mayor Michael R. Bloomberg had just won control of the city schools from Albany, and while Ms. Donlan was happy with her own children’s school, she knew that parts of the system were badly broken.

“Back then, people were hopeful, people were open-minded,” Ms. Donlan recalled this week.

But when Mr. Bloomberg announced this month that his next pick for chancellor wasCathleen P. Black, the chairwoman of Hearst Magazines, Ms. Donlan was outraged. She not only signed a petition asking the state education commissioner, David M. Steiner, to