This document provides a detailed description of the scope and sequence image. Many of the performance expectations (standards) are developed across units and sometimes across courses. They’re not necessarily fully addressed in one unit. These PEs are marked with the “*” or “+” on that image. The arrows on the image represent those connections where ideas are being built. Those arrows may also refer to connections in other ways, not necessarily just based on standards – an example could be B.1 and B.2, which are both focused on ecosystems. There will be intentional call-outs in B.2 to things that happened in B.1 regarding the phenomenon, activities, etc. More of these details can be found in the “Unit Overview” for each unit in the sections titled “Where does this unit fall within the OpenSciEd Scope and Sequence?” and “How will I need to modify the unit if taught out of sequence?” and “How does the unit build three-dimensional progressions across the course and the program?”.