The short answer: The NGSS are not grade-specific for middle school and there isn’t any determination by the NGSS for how the DCIs, SEPs, and CCCs should be bundled together and placed in the grades 6-8th. And using phenomena to drive instruction can be found throughout the Framework for K-12 Science Education So, the OpenSciEd developers, with input from the 10 Partner States, bundled the DCIs, SEPs, and CCCs based on how they would be needed by students to make sense of phenomena. Using phenomena to drive instruction can be found throughout the Framework. This supported the integration of all three disciplines (Earth, Life and Physical) to support the sensemaking about the phenomenon.

You can learn more about how the scope and sequence was determined for our program by watching this webinar. All that being said, our organization values teacher expertise. So the units are purposefully open resources and downloadable as easily editable Google docs so that teachers can modify as they see fit for their students.