What Are The 7 Crosscutting Concepts of NGSS?

Science education is full of abstract concepts, which is why it can be challenging for some students to grasp — particularly in middle school when the curriculum begins building upon foundational knowledge. As educators, we all know students need context and relevance to help connect these ideas to real-world experiences. And that’s exactly what the Next Generation Science Standards (NGSS) three-dimensional instructional framework aims to address through crosscutting concepts (CCC).

Crosscutting concepts are fundamental principles that determine how science and engineering professionals make sense of phenomena in our natural world. Teaching CCCs introduces recurring themes from STEM disciplines to help students begin viewing the world through a scientific lens.

CCCs have existed within science curricula for several years, but the NGSS instructional philosophy for integrating these concepts is relatively new. Since many teachers new to working with the concepts may have questions about how to effectively implement them, we're delving into what each crosscutting concept means and examples of how you might introduce these principles in a classroom setting.

1. Patterns

A pattern is a repeating event, design, or series of numbers. For example, the lunar cycle, DNA structure, or symmetry in plants are all patterns Learning to recognize patterns such as these helps students with analyzing and interpreting data, classification, and making predictions. It also encourages them to explore why patterns exist. And it’s an important place to start because patterns are essential to most other crosscutting concepts.

• Example:

The rain shadow effect is a phenomenon that happens when land on the downwind side of a mountain range receives less rainfall because the mountain blocks moist air flow. One way to help students observe this pattern is to have them record the average rainfall in various cities on either side of mountain ranges. Then, ask them if they notice a pattern in the data. Why do all cities on one side receive less rainfall than those on the other?

2. Cause and Effect

Identifying causal relationships is a crucial aspect of science and is essential for explaining phenomena. Understanding that a cause produces a result — and that effects are the results of specific actions — is the basis of experiments and investigations.

• Example:

Not all volcanic eruptions are the same. Some lava travels far from its eruption site, while lava from other volcanoes only travels a short distance. To understand this cause-and-effect relationship, here is an easy demonstration: w Pour different types of liquids down an inclined plane, then ask students to observe the speed at which each liquid travels and its viscosity. Then lead a discussion about how the demonstration can helpexplain volcanic eruption outcomes.

3. Scale, Proportion, and Quantity

Scale, proportion, and quantity help students make sense of phenomena that are too large or too small to easily observe. A scale is a representation with the same properties as an object — like, for example, using centimeters to represent miles on a map. Proportion refers to the relationship between two elements. For example, if a train travels 50 miles per hour, it will travel 250 miles in five hours. And quantity is the amount of something, such as temperature, speed, volume, mass, or time.

• Example:

The solar system is so large that we can only understand the size and distance between planets by studying models. And cells are so tiny that they must be studied under a microscope. You can ask students to observe cells and document estimated measurements using scale, proportion, and quantity.

4. Systems and System Models

A system is composed of parts that work together, like the human nervous system or the ecosystem of a rainforest. When students understand that each element of a system plays a role in the system as a whole,, they also understand that removing one component will impact the entire system.

• Example:

A simple Rube Goldberg machine, which performs a task by ensuring each event triggers another, can be easily built using inexpensive items and objects gathered from around the classroom. For example, you might start by dropping a rubber ball down a ramp, which collides with a row of dominos, which triggers a mouse trap, and so on. Ask students to test how moving or changing any single element will impact the system’s performance.

5. Energy and Matter

Energy is the power or ability to do work or cause change, and matter is anything that has mass and takes up space. Understanding how energy and matter flow in and out of systems is foundational to nearly every aspect of science and engineering.

• Example:

The law of conservation of matter states that matter cannot be created nor destroyed. Students can test this theory by measuring the mass of various materials before and after substances are heated, cooled, or mixed. For example, you might ask students to weigh a sugar cube and a glass of water separately, then weigh them again after dissolving the sugar cube into the glass of water.

6. Structure and Function

Structure refers to an object’s shape and composition, and function refers to its purpose. Learning these concepts will serve as the foundation for engineering and help students recognize that an object or living thing’s structure directly impacts its functionality.

• Example:

The double-helix shape of DNA isn’t an accident. This structure allows protein synthesis and DNA replication to occur. And a jet’s wings were engineered to be curved on top and flatter on the bottom to reduce air pressure on the top of the wing while increasing it underneath, which helps the plane move more quickly through the air. Ask students to observe the structure of other natural and human-made objects and explain how their structures impact their function.

7. Stability and Change

Changing something makes it different, while stability is the tendency to remain the same. Becoming familiar with these principles helps students understand that nearly everything in the natural world changes, but at different rates. And things that appear stable are often changing, but doing so at a nearly undetectable rate.

• Example:

Every technological innovation exists because of change, and each change is the result of a specific want or need. One way to illustrate this is to share a few processes, systems, and tools that have changed over the past 100 years. Like, for example, the objects we use to communicate or the tools we use to measure time. Ask students to explain the changes that occurred and the reasons behind them.

Additionally, you can explain how things that seem stable in nature are changing very slowly. Like, for example, a mountain slowly eroding over millennia or a large tree growing by just inches each year.

Covering all seven crosscutting concepts through engaging lessons and relevant examples isn’t easy — especially when teachers already have so much on their plates. And teaching CCCs in a way that supports different types of learners can be particularly challenging. To eliminate these headaches, Propello offers personalized science curriculum designed for the NGSS and aligned to state standards. With this solution, you can save time, regain your autonomy, and boost student outcomes.

Interested in trying it out? Sign up for a free account and discover what Propello can do for you.