Then it faded. Mr. Hidary said the effort has been winding down for the last year and a half. Its Twitter account has been silent for a year. Mr. Hidary nonetheless described the project as a success, a “catalytic initiative” that showed the way for other groups.

By design, the National Lab website made it easy to download curriculum materials and for teachers and scientists to connect, but it did not follow up to see how well everything worked in the classroom.

“We know we had direct influence on thousands and thousands of teachers,” Mr. Hidary said.

Mr. Hidary said he expected real improvements would take longer, and he was right. The scores of American students on the Program of International Student Assessment, last administered in 2012, have not budged much.

Mark S. Schneider, a vice president at the American Institutes for Research, a nonprofit research organization in Washington, was not a fan of Educate to Innovate in 2009, and still is not. “From my perspective, this has not gotten a lot of attention,” he said.

Plus, Dr. Schneider said, the STEM jobs challenge is not that the United States lacks academics with science doctorates, but rather that the country needs more people with two-year technical degrees to fill mid-skill positions, like for X-ray technicians. “It doesn’t seem we have addressed that in any serious way,” he said.

A successor to the National Lab Network is a new organization started last year, US2020, which is aiming to recruit one million volunteer mentors willing to commit to at least 20 hours a year working in the schools.

“We’re looking for sustained efforts,” said Eric Schwarz, executive chairman of the group. He predicted that school days eventually would get longer, and that outsiders might be teaching during many of those hours.