Look for: This is a good opportunity for formative asse…

7.A Develop two models to show relationships among the parts of the mostly closed cup system and how light and heat or cold (i.e., mechanisms) cause the liquid inside to warm up or cool down (effect).

This is a good opportunity for formative assessment of student understanding based on an examination of students’ models and claims. When analyzing students’ work, keep in mind that students bring more prior knowledge about light than heat, and their models should reflect this. Their models of light interactions with the closed cup system should be much more detailed and should include references to the concepts learned in the previous unit, Light and Matter.

• Likewise, their claims should include evidence gathered during this unit. In contrast, students’ models and claims in regards to heat energy or cold will more likely include references to their personal experiences.
• In either case, students’ work should give you information about what they do and don’t yet understand, which should guide your instructional decisions in the next few lessons.

When analyzing students’ models of light’s interactions with the cup system, look for evidence of student understanding of the following concepts:

• Light travels in straight lines.
• Light reflects, transmits, or is absorbed in varying amounts when it shines on the cups.
• If all or part of the light is absorbed, that light energy may be related to the temperature change or may turn into heat.

Because students have not learned about heat energy yet, when you analyze their models of heat and the corresponding claims, look for evidence that students are using their prior day-to-day experiences. Examples include these:

• Hot or warm objects cool down; cool or cold objects warm up.
• When hot or warm objects come into contact with cool or cold objects, the cooler objects warm up and the warmer objects cool down.
• Temperature tells us how warm or cool something is.

• If students are struggling with applying their understandings of light to this context, you may need to revisit ideas from Light and Matter and guide students in thinking more deeply about how to use what they know in Lesson 8.
• If students struggle with using personal experiences with heat to construct a model that predicts how heat might interact with the cup system, you may need to demonstrate how to use personal experiences with heat and cold to construct a model.

If students are struggling with writing a claim, or if they fail to support their claims with evidence and reasoning, they may need additional support. This could include providing sentence stems, providing a CER graphic organizer, or allowing students to work in pairs or small groups to write claims supported by evidence and reasoning.