"The Primary Evaluation of Essential Criteria for NGSS Instructional Materials Design. PEEC takes the compelling vision for science education as described in A Framework for K-12 Science Education and as embodied in the Next Generation Science Standards (NGSS) and operationalizes it for two purposes:

1. To help educators determine how well instructional materials under consideration have been designed for the Framework and NGSS, and
2. To help curriculum developers construct and write science instructional materials that are designed for the Framework and NGSS.

The resource seeks to focus both educators and curriculum developers on the critical innovations within the NGSS and dig deeply into materials to (1) evaluate the presence of those innovations and (2) answer the question "How thoroughly are these science instructional materials designed for the NGSS?" Educators can use PEEC to evaluate the NGSS design of comprehensive science instructional materials programs that include different units, kits, modules, textbooks, textbook series, and/or web-based instructional materials, including open educational resources. Meanwhile, PEEC enables curriculum developers to easily create and refine instructional materials, and to do so knowing that their efforts are focused on the same NGSS innovations that schools, districts, and states will be using to select their instructional materials.

Throughout PEEC, the word "designed" is intentionally used rather than "aligned." The word "designed" was chosen because it reflects the degree to which materials are consciously planned and deliberately organized to support the NGSS. For curriculum developers, this might mean starting from the beginning and building new materials, or it might mean significantly reworking existing materials. Either way, their focus should be to ensure that the NGSS innovations are a foundational aspect of, and clearly visible within, instructional materials.

PEEC was developed in a collaborative and iterative process managed by Achieve, including a public draft review in summer 2015 and small-group focused review sessions thereafter. Focus group feedback was provided by the following organizations: American Association of Publishers, Council of Chief State School Officers, Council of Great City Schools, Council of State Science Supervisors, Hands on Science Partnership, K-12 Alliance, National Science Education Leadership Association, and National Science Teachers Association.

Although PEEC was explicitly designed to evaluate materials designed for the NGSS, the innovations that are part of these standards are fundamentally rooted in the Framework. This means that states and districts that did not adopt the NGSS, but that adopted standards based on the three dimensions outlined in the Framework, should also be able to use PEEC to evaluate their instructional materials."