There is no textbook for developing a storyline for a STEM curriculum. However, a good starting point for an NGSSaligned curriculum is the performance expectation bundle (Krajcik et al. 2014). Combining performance expectations (PEs) together in a learning sequence allows students to make connections between different concepts (Achieve 2016).

After putting together PEs in a way that makes sense, it might seem strange that the first thing most curriculum developers do when they develop a storyline is to take the bundle apart. Deconstructing the PEs into their component dimensions—disciplinary core ideas (DCIs), science and engineering practices (SEPs), and crosscutting concepts (CCCs)—allows developers to see which elements might work well together. Although a PE may recommend combining a DCI with a particular SEP or CCC, a developer may feel that a different combination would create a more coherent storyline. Developers look for DCIs that will connect and identify those that will need more time to develop. They anticipate what students will need to know before moving to the next lesson. If they get it wrong, there will be a conceptual gap in student thinking. They then identify appropriate SEPs and CCCs that would help students make sense of these concepts.

The Glue That Holds the Pieces Together

As developers piece together the elements of the PEs, they are almost certainly starting to think of engaging phenomena and problems that could be used to link several lessons together. A good phenomenon or problem sparks curiosity. For it to involve sensemaking, it needs to be something that students can’t immediately explain or solve (Odden and Russ 2019). It should take extended classroom time for students to figure out (Penuel and Reiser 2018).

Students may need to develop understanding about science concepts before they can start solving a problem. For example, to design a solution to the problem of a playground surface being too warm to sit on, students first need to collect evidence that shows that sunlight warms surfaces. Then they need to design a shading device that will help stop the sunlight from reaching and heating up the playground surface.

A phenomenon or problem doesn’t always need to be familiar to students. Students could look at an image of a piece of silver jewelry from the Smithsonian African Art Museum and be asked to think about how it might be made from wax. Students are unlikely to have personal experience of lost wax casting, which is the process of making a metal object starting with wax wrapped in clay. However, the idea of a silver necklace being made from wax will spark their curiosity and make them want to learn more.

Most modules will need multiple phenomena and problems to cover the various elements in the storyline. Multiple problems will also ensure the engagement of a diverse group of students (Penuel et al. 2017). Selection of great phenomena and problems that work together to tell a story is a critical part of curriculum development.

Making Sense of Phenomena and Problems

It’s not sufficient to just have great phenomena and problems in a curriculum. A phenomenon and problem can’t just be for engagement. Students need to be actively engaged in figuring out a phenomenon or problem using the three dimensions of NGSS (EQuIP 2016). However, students do not come into school as blank slates. They will have ideas from their own experiences and background that they can build on.

Good phenomena and problems allow students to make connections to their everyday experiences (Penuel and Reiser 2018). Students may not be familiar with lost wax casting, but they may have experienced ice melting and objects made of wax, clay, and silver. It is up to the teacher to tease out these initial ideas (often called naïve ideas or naïve conceptions).

As students collect evidence, they build on their initial ideas through an iterative process of critiquing and revision (Odden and Russ 2019). Students use SEPs and CCCs together with DCIs as they make sense of phenomena and problems. For example, they may need to use a model or identify cause-and-effect relationships to explain how a tree becomes wet only on one side. As they build their content knowledge, they also build their proficiency in using SEPs and CCCs to help answer questions and solve problems.

Achieve. June 2016. The Next Generation Science Standards, For States, By States. “Bundling the NGSS.” Accessed August 2020: https://www.nextgenscience. org/resources/bundling-ngss

Educators Evaluating the Quality of Instructional Products. September 2016. “EQuIP Rubric for Lessons & Units: Science.” Version 3.0. Accessed August 2020: https://www.nextgenscience.org/sites/default/files/ EQuIP%20Rubric%20for%20Science%20v3.pdf

Kurin, R. December 17, 2014. Smithsonian Magazine. “For Every Object, There Is a Story to Tell.” Retrieved August 2020: https://www.smithsonianmag.com/ smithsonian-institution/for-every-object-there-is-storyto-tell-180953589/

Krajcik, J. S., S. Codere, C. Dahsah, R. Bayer, and K. Mun. 2014. “Planning Instruction to Meet the Intent of the Next Generation Science Standards.” Journal of Science Teacher Education 25(2): 157–175.https:// www.tandfonline.com/doi/full/10.1007/s10972-014- 9383-2

Odden, B., and R. Russ. January 2019. “Defining Sensemaking: Bringing Clarity to a Fragmented Theoretical Construct.” Science Education 103: 187– 205. https://onlinelibrary.wiley.com/doi/full/10.1002/ sce.21452

Penuel, W. R., and B. J. Reiser. 2018. “Designing NGSS‐Aligned Curriculum Materials.” Retrieved from paper prepared for the committee to revise America’s Lab Report, Washington, DC: National Academies Press: https://sites.nationalacademies.org/cs/groups/ dbassesite/documents/webpage/dbasse_189504.pdf

Penuel, W. R., K. Van Horne, J. Jacobs, T. Sumner, D. Watkins, and D. Quigley. 2017. “Developing NGSS-Aligned Curriculum that Connects to Students’ Interests and Experiences: Lessons Learned from a Co-Design Partnership.” Paper presented at NARST, San Antonio, Texas.

NGSS requires that students make sense of phenomena and problems using three dimensions. Smithsonian Science for the Classroom includes authentic phenomena and problems that draw on the rich resources of the Smithsonian as well as research and data from other scientific organizations. In each module, students actively engage in figuring out multiple phenomena and problems that will enable them to complete an end-of-module performance assessment. In figuring out these phenomena and problems, students gain in proficiency in using a small number of SEPs and CCCs that they will use in the end of module assessment.