Tag Archives: models

Transforming a Physics Lessons about Wave Properties

Are you transforming your physics course to NGSS? I took an old lesson of mine about properties of waves and transformed in to a phenomenon-driven storyline.

The original activity was an inquiry-based lesson on wave properties. You can find it on the PhET website. I wanted to update this lesson to align with the NGSS vision.

The first thing I needed to do was identify an anchoring phenomenon for my topic. My focal NGSS performance expectation is HS-PS4-1. I wanted to use the Waves on A String simulation again, so I needed a phenomenon that would fit. I found this video on YouTube.

The video provides a perfect opportunity for students to notice patterns between the waves on guitar strings and the sounds that they hear. I decided to use this as my anchoring phenomenon. I asked students:

  • What patterns do you notice in the video? 
    • What do the patterns on the strings look like as they are being played? 
    • Do you notice any relationships between the patterns of what you hear and what you see? 
  • What do you think causes those patterns?
  • Create a model to record your ideas using this Google Jamboard.

I frame the students initial ideas about the phenomenon in terms of the crosscutting concepts. In high school, students are expected to use empirical evidence to identify patterns.

This opening activity creates curiosity about the phenomenon and prompts students to ask questions about the relationships among wavelength, frequency, amplitude, and the medium (the guitar string).

The original sequence is a good fit for students to figure out how and why different guitar strings produce different sounds as they also address the content of HS-PS4-1. Here is a link to the finished lesson.

Let me know what you think about this lesson!


Waves on a String by Lori Andersen is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Based on a work at https://drloriandersen.com/main/waves-on-a-string/.

Crosscutting Concepts

By Dr. Lori Andersen, June 2020

The crosscutting concepts are the “thinking tools” of science. These seven big ideas help us describe and explain our world. Why is it important to use them as a set rather than individually, as they are presented in the standards?

A phenomenon is an object, process, or event. A phenomenon can be something very ordinary. It doesn’t have to be anything phenomenal. All phenomena are either a system or a part of a system. This is why systems and system models is the foundational crosscutting concept (Rehmat et al., 2019) and the arrow in the diagram points from phenomenon to systems and system models.

Systems and system models are tools for describing and explaining systems. A system model is a representation of the components and how they interact. The systems model can include pictures and text. The most important feature of the systems model is that it explains how the phenomenon happens.

Patterns are tools for describing what happens. There are many different kinds of patterns we might notice. We describe patterns using two other crosscutting concepts — scale, proportion, & quantity and stability & change.

Cause and effect is a tool for explaining why something happens. Cause and effect relationships can be simple or complex. We explain cause and effect using two other crosscutting concepts — matter & energy and structure & function.

The diagram provides a way to think about how the CCCs operate together as we create system models. In phenomenon-driven instruction, we are going to use many CCCs rather than just one or two. The idea for this diagram came from Rehmat et al. (2019) and I modified it to include phenomenon and adjusted the representation of systems and systems models in the diagram.

By NASA, ESA, AURA/Caltech, Public Domain, https://commons.wikimedia.org/w/index.php?curid=7805481

Let’s apply the set of CCCs to an example. One phenomenon is the rising of Makali’i every November, which is used to mark the beginning of the Hawaiian new year.

Makali’i is a group of stars. We see the stars because light from the stars travels to our eyes. Our system model needs to include the stars, sun, and Earth to explain why we see them.

I developed this diagram using the templates on Paul Anderson’s website, Wonder of Science. These are great tools because they are already Google Draw editable documents. I added my system components and supporting text.

This system model explains how we can see Makali’i in November. Components include: Makali’i, sun, Earth, and observer. Makali’i emits light, which travels to Earth so we can see Makali’i in November. How do we use the other CCCs in the model?

Patterns are what happens in the phenomenon. There is a time pattern of specific months of the year when Makali’i can be observed in the sky. The time is measured with units (Scale, Proportion, & Quantity). Constellation patterns stay consistent over shorter periods of time, such as a month, while changing quite a bit over longer periods of time, such as a year (Stability & Change).

Cause & Effect is why the phenomenon happens. There is a cause, or reason, for the effects we observe. We observe Makali’i because the light can reach our eyes. The light can reach our eyes because the arrangement of sun, earth, stars, and the observer creates an unobstructed path for starlight. Light is a transfer of energy (Matter & Energy). The unobstructed path happens because of the structure within the system (Structure & Function). The Earth itself blocks light from reaching our eyes depending on its position in its orbit and its point in the rotation on its axis.

In the example of observing Makali’i, we see that all the crosscutting concepts play a role in describing and explaining the phenomenon. This diagram shows the role of each crosscutting concept.

So, how would you decide which to leave out? How can we use them together without overwhelming students and teachers?

What do you think about using all the crosscutting concepts in creating systems models that describe and explain phenomena? Leave your ideas in the comments!

References

Rehmat, A.P., Lee, O. Nordine, J., Novak, A.M., Osborne, J., & Willard, T. (2019).  Modeling the role of crosscutting concepts for strengthening science learning of all students. In S. J. Fick, J. Nordine, & K. W. McElhaney (Eds.), Proceedings of the summit for examining the potential for crosscutting concepts to support three-dimensional learning. University of VA. http://curry.virginia.edu/CCC-Summit