The U.S. Department of Education has invited 124 organizations to apply for the smallest—and most popular—of the Investing in Innovation grants, which are intended to scale up promising practices at the district level.

This is the first time the department has done a “preapplication” for the “development” grants. Development-grant applicants don’t need to meet as high a research threshold as those in the other grant categories—they just need to have “reasonable research-based findings or theories.”

Development grants can be as much as $3 million. The other two categories are “validation” grants, which can be as high as $15 million each and go for programs with “moderate” level of evidence. “Scale up” grants of up to $25 million are for programs that have “strong” evidence of success.

The department received more than 650 preapplications. Of those invited to apply, 23 focus on teacher and principal effectiveness; 39 deal with Science, Technology, Engineering, and Math education; 32 stress parent and family engagement; 20 are aimed at school turnarounds; and 10 focus on rural education.