One reason is that it helps teachers see how students might start to make sense of the same science that they just explored during the Science Investigation. By connecting their own understanding to what students do and do not know, and by questioning any ideas that are unclear, teachers have another chance to chew on the science for themselves. Even when we feel like we know the science inside and out, taking a careful look at related student work and discussing our interpretations with peers inevitably adds another layer to our understanding. The more facets of the science we can see, the more completely we own the content.
One aspect of this convention is that student work is marked up publicly — typically on a chart that depicts the student work. This is to help the group see the diversity in each other’s interpretations, to call attention to misconceptions, to highlight where a student has made progress, and to brainstorm just the right follow-up question one might ask the student.
To mark up the work, we use a three-color system: