About 300 parents and educators came to Baldwin School on Wednesday evening to hear an unusual education reformer - director M. Night Shyamalan - talk about his ideas for closing America's achievement gap.

The Philadelphia-area filmmaker has long had an interest in education and recently wrote a book, I Got Schooled, based on his education foundation's research into ways to help poor inner-city students reach the same educational heights as those at a school like Baldwin, an all-girls private school in Bryn Mawr.

"Accountability alone has never been shown to raise student achievement. That's not the problem," Shyamalan said in a question-and-answer session after mingling with local educators.

He said there are five keys, which must be employed together, to improving student achievement: identifying great teachers and remove bad ones, promoting instructional leadership, providing consistent feedback on teaching practices, reducing school size, and adding teaching time to the school day and year.

He called these "best practices" essential for producing good schools.

His book, which has gotten the attention of politicians and policy makers here and in Washington, is based on 4 1/2 years of research, he said. He started it after he and his wife offered college scholarships to five top students from Philadelphia high schools.

"I thought I was going to meet five Martin Luther Kings," he said. Instead, he confronted "five scared kids who were pushed through the system." He challenged his foundation to find an inner-city, high-poverty district where students were making great strides.

"There is none," said Shyamalan, whose wife,  Bhavna, accompanied him to the event.

Philadelphia City Councilman Bill Green, Gov. Corbett's pick to lead the School Reform Commission, has said he was heavily influenced by Shyamalan's book and wants to incorporate its lessons in city schools.

"It's a compendium of the best data and evidence that exists out there," Green said in an interview earlier Wednesday. Shyamalan's research demonstrates that closing the achievement gap "can be done." But for the ideas to work, "all the stakeholders have to cooperate. If they don't, I'd say we can't be successful," Green said.

Most Philadelphia elementary schools are already small since their student enrollments are below the maximums, he said.

Linda Cliatt-Wayman, principal of Strawberry Mansion High School, said Shyamalan's ideas are good but costly.

"These are not new ideas. They've been implemented in Philadelphia schools, but we can't sustain them because it costs a lot of money," she said at the gathering for educators.

Others agreed that the five keys that Shyamalan touts are tried and true methods but have been packaged in a way that is accessible to the general public.

"The way he simplifies it and boils it down to key components," said Sally Powell, Baldwin's head of school, "helps fuel the way for a broader audience to look at it."

kboccella@phillynews.com 610-313-8232 @kathyboccella