Look for: While analyzing class data in small groups an…

3.B Use evidence to modify a model to explain how an object’s material (structure) influences the path of light as it transmits through or reflects off the material (function).

While analyzing class data in small groups and as a class, look and listen for students to

use light data to compare the one-way mirror to the regular mirror and glass, and

create a continuum and place each material along the continuum based on the amount of light each transmitted and reflected.

When students individually complete their Progress Tracker, look for the following ideas in their representations:

• Light travels in a straight line.
• When light shines on the one-way mirror, about half of the light reflects off, which is slightly more than the amount of light transmitted.
• The one-way mirror does not reflect as much light as a regular mirror, and it does not transmit as much light as a window.

The Measuring Light Investigation gives students the opportunity to analyze and use quantitative data to make sense of the one-way mirror phenomenon.

If students struggle to analyze the data and compare the one-way mirror to glass and the regular mirror, you can help them with these steps:

• Simplify the data on slides U and V (e.g., select one set or use an average).
• On chart paper, use the data to build a key, then put numbers on a continuum.
• Use the scale on the continuum to compare the materials, focusing first on the amount of light transmitted, and place each material on the continuum before moving on to the amount of light reflected.

While revising the consensus model, if students struggle to represent what they observed, guide them to build the model using a systematic process such as this:

• Determine how to represent the scale and key on the continuum with solid and dashed arrows.
• Focusing on one material at a time, draw each in a zoomed-in bubble.
• Then, represent light (using a solid straight arrow) coming into contact with the material.
• Next, represent what light does after it hits the material using dashed arrows, as appropriate based on the data.
• Repeat the process with each material.

If students struggle to complete their Progress Tracker, remind them to use their observations in their notebook, as well as charts around the room, for support. You can also allow students to work with a partner if needed. In addition, you can use what you learn from students’ work in the Progress Trackers to inform your next steps for moving their thinking forward. This could include

giving students feedback in their notebooks, such as additional probing questions, suggestions for improvement, or a request for additional evidence or reasoning;

revisiting, reteaching, or reinforcing ideas from the lesson to help students fill in gaps in their learning;

using examples of actual student work to prompt discussion about what we have and haven’t figured out up to this point; and

asking additional questions at the beginning of the next lesson to probe students’ thinking and help them make connections and build understanding.