I’ve worked with several schools that are framing their curriculum and units of instruction around big ideas, key understandings, generative topics, or themes (the terminology depends on which model is being used). The rationale for using an overarching concept is that it helps to pull together a disjointed set of topics, provides a focus for instruction, and helps students see connections among concepts.
If you’re struggling to find a “big idea” in science, look no further than this month’s issue of Science Scope. for resources on the concept of Change. Think of how many science topics include changes: plant and animal life cycles, the seasons, acceleration, the rock cycle, climate change, weather, the night sky, motion, chemical and physical changes, reflection and refraction, evolution, and the list goes on (feel free to add more). If there’s a constant in science, it’s the idea of change (discuss that over a cup of coffee some time!).
If you enter the word “change” as a SciLinks keyword, you’ll see a list of topics. Among them are the ones highlighted in the journal:

• Changes in Climate
• Changes in Ecosystems
• Changes in the Earth’s Surface
• Changes of Properties in Matter
• Changes of State

Wikis, Moodles, blogs, Face Book, podcasts, Smart Boards – just look at the changes in technology applications and resources that are available to teachers and students to access and share information. Whether it’s a fact-to-face or online, professional development is changing, too, from one-shot “sit and git” presentations to more focused and intensive projects that are related to and embedded in actual practice.
The overemphasis that some are placing on standardized tests and changes in the economy that are forcing schools to make hard decisions illustrate that not every change is positive, of course. And there are those who lament that students aren’t the same as they used to be. I’ve heard this comment for a zillion years. I’d be curious to know when there was a time when students were not changing!