ProPublica and USA Today are teaming up to cover a neglected sector of American K–12 education: a vast and growing system of “alternative” schools. These schools are made up of roughly half a million of the nation’s most vulnerable students, and as our initial reporting shows, many are getting a second-tier education.

Alternative schools have long served as disciplinary placements. But since the No Child Left Behind Act of 2001 refashioned the yardstick for judging schools, alternative education has taken on another role: A silent release valve for high schools that are straining under the pressure of accountability reform. In some districts, regular schools are sending low achievers to alternative charter schools run by for-profit companies.

We know what some of the warning signs look like – and we’ve identified 83 school districts that had both a significant rise in their alternative population and the graduation rate of traditional schools at the same time during a recent four-year period. If you live in one of these hotspots, we'd really like to hear from you – whether you've got students in the public school system, work in a school district, or are acquainted with one of these schools yourself.

Please fill out this survey to help us figure out where to look next.

A note about our commitment to your privacy: ProPublica and the USA Today network are gathering these stories for the purposes of our reporting, and will not share your information with third-parties without your express permission.