When I hear a student who can parrot back to me something I’ve told them, I don’t feel very inspired, but if I hear students sharing ideas and thoughts that they’ve never heard from me, and that represent a deeper understanding of the things we’ve studied together… now THAT is inspiring! In a recent lesson that I observed , 8th graders were talking about density as a characteristic property (a property that doesn’t change with sample size). Some of them thought that a bigger piece of wax would have a greater density. One student in particular, Tammie, thought density should “get bigger” if the piece of wax was bigger. She was convinced of it.
Tammie was not alone, but in her written conclusion to the experiment, she concluded that the density of the wax increased as volume increased. Her calculations were based on measurements that were just as imperfect as almost any 8th graders’. The students were asked to plot the wax with a few other materials on a graph and to study the similarities and differences they noticed. I don’t know what Tammie had said with her group at first, but she was very animated. I heard her say “ but that can’t be right!” As I approached, I saw her face change. Tammie’s eyes went very wide. Her mouth hung open. And I watched the corners of their lips pull up and stretch her mouth into the widest smile in the room! “I get it!” she said. “I get it! I thought density was increasing, but these other things… some of them increased and some decreased but all of it just a little bit… like, so little it doesn’t matter! They’re all the same!”
Think about that for a moment. In writing, she didn’t get it. But in talking about it, in that quick interaction that allowed her to explore many ideas in a short amount of time, she had a revolution in her understanding not JUST about reliability of measurements, but also of the nature of this one characteristic property.
At the heart of the Next Generation Science Standards (2013 WSSLS) lies making meaning: either through explaining phenomena or through developing solutions to problems. Because student talking is thinking, we want to engage as many students as possible in the practice of academic discourse.
Mark Windschittl’s Ambitious Science Teaching group at University of Washington has an excellent resource that teachers can use that explores the different reasons why they may want to engage students in discourse; the nature of question types that can deepen student understandings; and some “teacher moves” that they can intentionally practice to keep kids talking so they can keep making sense of phenomena or designing solutions.