Understanding The Three Dimensions Of The NGSS

What exactly ARE the “three dimensions” of the Next Generation Science Standards?

ngss three dimensionsIf you’ve been around the NGSS long enough, you’ve heard of its three dimensional nature. Honestly, that term is kind of thrown around.. three dimensional assessments. Three dimensional learning. Three dimensional tasks and instruction. “The Three Dimensions.”

But what does that actually mean for your everyday practice? How do you actually teach three dimensionally?

Before we answer that, let’s just get in the same page about what the three dimensions really are.

The Three Dimensions

The first – Disciplinary Core Ideas is really the easiest to understand. It’s the content.  And if you’ve been following this blog, you should already know — it’s the BIG IDEAS in the content.  

The second dimension – the Crosscutting Concepts – are trickier to understand.  These are overarching ideas that cross disciplines and topics. Things like patterns… systems… cause and effect.  They can be tied to any number of topics and provide a “lens” through which we can understand a phenomenon. For example, students may explore a described series of events related to a change in an ecosystem, considering this phenomenon through the Crosscutting Concept of Cause and Effect.  In my Predicting Changes In Ecosystems activity, students utilize a graphic organizer to help them make sense of the phenomenon through the lens of the Crosscutting Concept. This type of explicit instruction is necessary, because while we oftentimes naturally see these connections, our students just as often do not.

As adults, and specifically as science teachers, we see cause and effect relationships, we notice patterns in data, we understand that in a system one thing affects another…  And we often assume our students see these connections, too.  Unfortunately, that’s not always the case, and for that reason, the NGSS expects teachers to make these connections explicit.  To teach the Crosscutting Concepts as they apply to content to help students develop a more scientific way of viewing and thinking about the natural world.

Science and Engineering Practices

The third dimension (also, these are in no particular order, despite my reference to first, second and third anyway), the third dimension is the Science and Engineering Practices.  These are the skills scientists use every day to understand our natural world, and it’s these skills that we want our students to master before they graduate. In the past, these skills were often taught via the “scientific method” or in a unit on “inquiry.”  They were often isolated in your district and state standards under those same headings.

While some of the skills might be the same, these skills are FAR FROM isolated in the Next Generation Science Standards.  They are literally woven into the standards themselves — into the Performance Expectations. Each Performance Expectation targets at least one of these skills, so in order to truly meet the standards, students must demonstrate the skill.

What skills are we looking at here? For example, students might be analyzing and interpreting data, developing a model to represent a system, or constructing an explanation based on evidence.  These are the science practices that students will need to demonstrate a mastery of in order to fully meet whatever standard you are targeting — the content is just one piece of their assessment.

The Three Dimensions In Practice

Now, in order for that to happen — in order for students to actually master these skills — they can’t just be taught in a “scientific method unit” at the beginning of the year.  Even engaging students in lab activities once or twice a month isn’t enough. No, these skills must be included in each and every class — and not as an extra activity, a warm-up, exit ticket, or homework assignment.  No, these skills must be tied directly to the content students are investigating daily.

And this is where your BIG change in instruction happens. This is what the NGSS is all about. If you’re not changing your instruction to truly address ALL THREE dimensions of the NGSS — if students aren’t using the practices to discover the content — then you haven’t really adopted the standards.

If you’re ready to dive into NGSS professional development that goes beyond the WHAT and gets into the HOW, be sure to check out the Science Teacher Tribe Course + Community. Get a preview of what professional development inside the membership is like by enrolling in the free mini-course, Intro To The NGSS, today!

ngss three dimensions