Bill & Melinda Gates Foundation co-founder Bill Gates speaks onstage during Goalkeepers: The Global Goals 2017 at Jazz at Lincoln Center on Sept. 20, 2017, in New York City. (Jamie McCarthy/Getty Images for Bill & Melinda Gates Foundation)

Bill Gates has a(nother) plan for K-12 public education. The others didn’t go so well, but the man, if anything, is persistent.

Gates announced Thursday that the Bill & Melinda Gates Foundation would spend more than $1.7 billion over the next five years to pay for new initiatives in public education, with all but 15 percent of it going to traditional public school districts and the rest to charter schools.  (When he said this, the audience at the 2017 conference of the nonprofit Council of the Great City Schools applauded, perhaps because many education philanthropists direct the bulk of their education giving on charter schools, which are publicly funded but privately operated. Gates supports them as well.)

He said most of the new money — about 60 percent — will be used to develop new curriculums and “networks of schools” that work together to identify local problems and solutions, using data to drive “continuous improvement.” He said that over the next several years, about 30 such networks would be supported, though he didn’t  describe exactly what they are. The first grants will go to high-needs schools and districts in six to eight states, which went unnamed.

Though there wasn’t a lot of detail on exactly how the money would be spent, Gates, a believer in using big data to solve problems, repeatedly said foundation grants given to schools as part of this new effort would be driven by data. “Each [school] network will be backed by a team of education experts skilled in continuous improvement, coaching  and data collection and analysis,” he said, an emphasis that is bound to worry critics already concerned about the amount of student data already collected and the way it is used for high-stakes decisions. In 2014, a $100 million student data collection project funded by the Gates foundation collapsed amid criticism that it couldn’t adequately protect information collected on children.

Gates praised the Common Core State Standards, which he essentially made possible by spending hundreds of millions of dollars to fund its creation, implementation and promotion. He said his foundation would continue to support the development of quality curriculums and professional development related to the Common Core, which was initially a bipartisan effort adopted by most states but later became politically charged and controversial, with some states dropping the standards or changing the name.  (President Trump and Education Secretary Betsy DeVos say they are opposed to the Core — which was adopted by most states — and want to eliminate it, but only officials in those states can decide to replace it.)

Education philanthropy is a time-recognized tradition in the United States, though it has become increasingly popular among America’s superwealthy since Gates started in 2000. This has raised questions about whether American democracy is well-served by wealthy people pouring so much money into pet education projects — regardless of whether they are grounded in research — that public policy and funding follow. That concern has been directed most pointedly at Gates, because his foundation  has spent the most by far on education philanthropy, and because he was pivotal in advancing some of the controversial priorities of the Obama administration’s Education Department.

Gates has underwritten a number of projects that have had less-than-desired results, which he has conceded over the years as he moves from one to another, sometimes acknowledging mistakes made. In 2014, he gave a nearly hour-long interview at Harvard University in which he said, “It would be great if our education stuff worked, but that we won’t know for probably a decade.”

On Thursday, Gates said he will no longer fund a major multiyear project to create teacher evaluation systems that in part use student standardized test scores, a method experts said shouldn’t be used for such high-stakes decisions. The Obama administration pushed the effort, which became highly controversial and led to a rebellion among parents, students and teachers against high-stakes standardized tests. After giving hundreds of millions of dollars to some school districts to create these programs, Gates seemed to realize in 2013 that things weren’t going as planned, and he wrote in an op-ed in The Washington Post:

As states and districts rush to implement new teacher development and evaluation systems, there is a risk they’ll use hastily contrived, unproven measures. One glaring example is the rush to develop new assessments in grades and subjects not currently covered by state tests. Some states and districts are talking about developing tests for all subjects, including choir and gym, just so they have something to measure.

The teacher evaluation project came after an expensive three-year project that was designed, as a foundation news release said, “to determine how to best identify and promote great teaching.” Part of it involved videotaping teachers and giving surveys to students to see what engaged them in class. The news release said the project “has demonstrated that it is possible to identify great teaching by combining three types of measures: classroom observations, student surveys and student achievement gains.” That, after millions of dollars spent.

The effective teaching project followed the foundation’s $650 million investment, which began in 2000, to create small schools in New York City.  The foundation dropped the effort nine years later. Why? The foundation’s 2009 annual letter said, “The hope was that after a few years they would operate at the same cost per student as before, but they would have become much more effective,” and, “Many of the small schools that we invested in did not improve students’ achievement in any significant way.” However, on Thursday, Gates said something different. In his speech, as prepared for delivery and provided by the foundation:

In New York City, graduation rates of students attending small schools was more than 30 percentage points higher than the schools they replaced. And almost half of the students attending small schools enrolled in postsecondary education — a more than 20 percent difference from schools with similar demographics.

In his speech, Gates said that education philanthropy was difficult, in part because it is easy to “fool yourself” about what works and whether it can be easily scaled. He closed his remarks with this:

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. We will not stop until this has been achieved, and we look forward to continued partnership with you in this work in the years to come.

Gates is an innovator, and innovators like to try things and move on if something doesn’t work. In business, that can work well, but it is hard to negotiate in education, where children are the focus and experimentation can be difficult and result in unintended consequences that can be harmful.