For most of her 18 years as a teacher, Diana Lininger had her performance evaluated in just one way: Her principal visited her Pittsburgh classroom twice a year.

A few months ago she got a far different sort of review, though she was a bit hesitant about the idea at first. Lininger's teaching skills were rated by her sixth-grade students.

The children answered a battery of questions about how well she explained things, whether she used time efficiently, and whether she made them want to try their hardest - all part of a massive research project on what makes an effective teacher.

The effort is funded by a man who was a pretty fair student in his day, though he famously dropped out of Harvard to focus on the new world of computers: Bill Gates.

The cofounder of Microsoft Corp. is getting an award Thursday from the Franklin Institute, honoring him both for building the software giant and for his more recent foray into philanthropy. Ten other science and engineering standouts will receive awards during the black-tie ceremony, an annual event that dates to 1824.

Gates, 54, had his first exposure to computers in 1968, while in eighth grade at Seattle's Lakeside School. He and a core group of other students spent countless hours teaching themselves to program - and even hack - such machines, and some eventually came to work at Microsoft. He and fellow Lakeside alum Paul Allen founded the company in 1975, and Gates soon left college to work there full-time.

The company's software is now ubiquitous, and Gates is perennially ranked among the world's richest people. He remains chairman of the company but stepped down from day-to-day responsibilities in 2008 to focus on the Bill and Melinda Gates Foundation.

The bulk of the $22 billion committed thus far by the foundation has gone toward fighting disease and poverty in developing nations, with the money donated by the Gateses themselves and more recently by the investor Warren Buffett. But increasingly the huge nonprofit is getting attention for its work on a thorny problem at home: public education.

Among other efforts, it has invested in programs that seek to improve college graduation rates and remedial instruction at community colleges, and it has funded scholarships for high-achieving, low-income students of color.

Determining what makes a good teacher is one of the foundation's newest aims. It's a simple-sounding goal but one that has been hard to nail down.

"Nobody really knows what it is," said Daniel Weisberg, a former New York school official who is now vice president of the nonprofit New Teacher Project. "Nobody's been able to bottle what it is about Teacher A that produces results."

Nevertheless, the impact of a quality teacher has been shown numerous times. In one study, students with teachers in the bottom quarter, performance-wise, dropped 5 percentile points on test scores when compared with others in the same demographic group. Students with teachers in the top quarter, meanwhile, gained 5 points during the school year.

That is a much larger effect than just about any other measure that has been studied, including class size and the size of the overall school. An early project of the Gates Foundation was to fund the creation of small schools, but the results were mixed.

So in late 2008, the foundation unveiled its two-year, $45 million Measures of Effective Teaching project, headed by Harvard researcher Thomas Kane - a coauthor of the study that found the 10-point achievement swing. The project got under way during the current school year, with nearly 3,000 teachers agreeing to participate from six districts around the country. Each gets $1,500 for his or her efforts.

In addition to the student feedback, the teachers are being subjected to a half-dozen other measures. Their classes have been videotaped and rated by experts. They are being asked for their own opinions of their abilities and of working conditions.

All of this data will be scrutinized to see what practices have the most impact on student test scores.

Gates has acknowledged that such measures could someday be used to identify teachers who don't belong in the profession. But foundation officials say the bigger goal is to help teachers improve. Local teachers' unions have signed on.

Lininger, who teaches reading and English at Pittsburgh Classical Academy, was initially unsure about volunteering. What if a student held a grudge?

"What happens if he had a bad experience in my class the day before, and now he's writing me up just because of that one incident?" she recalled thinking.

But she was reassured to learn that the results were strictly for research and would not be shared with district officials.

Lininger will not be told about the responses from individual students. But she will get aggregate numbers, which she hopes will help her improve her craft.

That's also the hope of Cristina Fernandez, a high school English teacher in Florida's Hillsborough County district.

So far Fernandez has been videotaped three times in her classroom at Sickles High School in Tampa. She sometimes forgets the camera is there, she said.

Kane, on leave from Harvard to serve as a deputy director of the Gates Foundation, said the videos are analyzed for a variety of things, such as whether the teacher begins the class with a clear objective. While some teacher skills may come naturally, Kane suspects that many techniques that turn out to be effective will be usable by anyone. They just need to be pointed out.

Improving education is perhaps a muddier problem than writing a computer program or funding the trial of a new vaccine. But Gates seems determined to bring a similar scientific approach.

"Doctors aren't left alone in their offices to try to design and test new medicines," he said when the program was announced. "They're supported by a huge medical-research industry. Teachers need the same kind of support."

Separately, the foundation has pledged $290 million to "intensive partnerships" in four school districts, including Pittsburgh. These dollars are designed to allow the districts to reinvent how they recruit, train, reward and retain teachers - again with union and teacher input.

Though Gates left Harvard without a degree, he was a star student when he put his mind to it. At Lakeside, he excelled at math and English, among other subjects, recalled Fred Wright, who taught him honors geometry.

Wright, who is now retired, considered himself a good teacher. But with young Bill Gates, in one area the roles were reversed.

"Actually," Wright said, "he taught me a lot about computers."