How we review materials

Free curriculum sites have a documented quality problem. Reviews of the most-downloaded supplemental materials on major platforms have found weak teacher guidance, standards tags that do not match the content, and little support for diverse learners. This page describes how we work on that problem, and it is also honest about the limits of what a growing library can promise.

How materials are made

Materials on this site are drafted based on publicly available information, including official standards documents, government and industry references, and operator training materials, and are adapted for classroom use on this site. Every material follows the same structure: named standards with a written note on how the material aligns, learning objectives, an estimated time, an answer key or scored rubric, and a differentiation section with supports for below-grade readers, extensions for advanced students, and scaffolds for English language learners.

The checks we run

Before publication, each material passes through a set of consistency checks: the structure is verified against the format described above, standards codes are checked against the official text, quantities and regulatory values are checked against a maintained list of sourced figures with as-of dates, mathematics in answer keys is re-worked separately as a cross-check, and materials are compared against the rest of the library so that they remain genuinely distinct. Facts that can change, such as regulatory limits in transition, are dated in the material itself.

What we can and cannot promise

The process is challenging, and we attempt to have materials reviewed and double-checked by volunteers. However, not all materials have been reviewed at this time, and no process catches everything. Materials here may contain errors, and teachers should always use their best judgment when selecting, using, or adapting materials for their classrooms. Everything on the site is in the public domain, so teachers are welcome to adapt any material to fit their students.

When an error is found, we correct it for every future reader.

The external directory

Entries in the directory are annotated descriptions of other organizations' work: what a site offers, which grades it fits, and whether access is free. We check links periodically and show the date of the last check on each listing, but we cannot continuously verify the contents of other organizations' sites, and their materials carry their own terms and their own quality practices.