CLEVELAND, Ohio - Microsoft founder Bill Gates told leaders of the nation's big-city school districts today that he is looking for creative use of data, charter schools and a few "big-bet" innovations to make the biggest difference in improving education in the next few years.

Gates, who has spent millions of dollars on education causes over the last decade through the Bill and Melinda Gates Foundation, gave a lunchtime talk at the Council of the Great City Schools national conference here in Cleveland moments ago.

The 40-minute talk was very policy-focused and aimed at his specialized audience, with a few broader comments.

His main goal, he said , is not to just help pay for schools, but to fund pilot programs that have potential to be expanded on a great scale and help many more students down the road.

"Our role is to serve as a catalyst of good ideas, driven by the same guiding principle we started with: all students - but especially low-income students and students of color - must have equal access to a great public education that prepares them for adulthood," he said. "We will not stop until this has been achieved."

See his prepared speech HERE. He had additional comments that are not included in this text.

Gates said his investments have not always brought the results he wanted. But he said they all had valuable findings that led to improvements.

He also outlined how he hopes to invest $1.7 billion over the next five years on education.

Here's a quick look at his plans:

- Twenty-five percent, he said, "will focus on big bets - innovations with the potential to change the trajectory of public education over the next 10 to 15 years."

These can include better use of technology, research in early learning, or "promising developments in neuroscience, cognitive psychology, and behavioral economics."

- Fifteen percent will go toward charter schools - the often-controversial privately-run, but tax-funded public scholols.

"Our emphasis will be on efforts that improve outcomes for special needs students - especially kids with mild-to-moderate learning and behavioral disabilities," Gates said. "This is a critical problem across the education sector, and we believe that charters have the flexibility to help the field solve this problem."

- Sixty percent of the money, by far the biggest piece, would go to support "networks" of schools that propose new ways of using data to identify students that need special help and then find ways to reach these kids.

These networks can be districts, charter chains, or a colection of schools or small districts. They can be linked with an outside organization that helps them, or not.

They will propose ideas to the foundation, he said, rather than being directed by the foundation.

"We believe this kind of approach - where groups of schools have the flexibility to propose the set of approaches they want - will lead to more impactful and durable systemic change that is attractive enough to be widely adopted by other schools," Gates said.

He pointed to efforts in Fresno to encourage more students to apply to college, research in Chicago that has helped more students enroll in college and work by the Summit charter school chain in California and Washington to help English Language Learners as strong examples of initiatives he hopes to support.

The study of evaluating teacher performance - perhaps his most controversial effort - will be mostly put aside, he said.

"Although we will no longer invest directly in new initiatives based on teacher evaluations and ratings, we will continue to gather data on the impact of these systems and encourage the use of these systems to improve instruction at the local level," Gates said.

That three-year study, called Measures of Effective Teaching (MET), was aimed at identifying strong teachers, finding ways to measure them and teach their methods to others. It drew loud complaints from teachers, who viewed it as a push to overanalyze and blame them.

Gates said that study showed that evaluating teachers is still "critical" to helping students learn more. He also noted that it led to some states and districts to use surveys of students as part of the evaluations. Ohio does not require that, but allows districts to include them.