During the class, listen to the ideas students offer in step 8 of the activity. Do students’ predictions follow the rules? At this point, do not correct student ideas, but listen for what they say about matter and energy in the context of plant growth. After class, use the 3.1 Assessing the Predictions Tool for Plant Investigations to compare your students’ work with what we would expect to see in Level 4 responses.
Ideally, the discussion about the Predictions and Planning Tool in this activity will reveal a range of student ideas. Some students will have Level 2 ideas with respect to the principles (matter and energy) and context-specific knowledge (how a plant grows). Listen to see if students have a sense of necessity about connecting mass changes and movement of atoms, and if they recognize that if the plant gains mass, then atoms must be moving into the plant. Also, listen to see if students account for energy separately from matter (Levels 3 and 4), or if they suggest that some of the matter in the plants might be converted to energy (Levels 2 and 3). You do not need to correct any problems now; they will be addressed through the investigation and modeling in the activities to come.
- Have a designated place in the classroom where students store their Expressing Ideas and Questions and Predictions and Planning Tools so they can easily refer back to their ideas at the end of the lesson.
- Expect some students to make the right predictions for the wrong reasons. Note in particular whether they say that changes in the mass of the gel indicate that atoms are moving.