Pressing students for evidence-based explanations
This discourse tool helps you design conversations that aids students in co-constructing evidence-based explanatory models for some natural phenomenon. This phenomenon could be 1) the focus of a MBI that students have engaged in over the previous few days (e.g. what makes a candle draw up water in an enclosed container), or 2) of a phenomenon for which students have primarily second hand data (e.g. why asthma is so prevalent in poor urban communities).
This conversation usually comes after you’ve allowed students to create some initial models of the key phenomenon, given them some data collection experience, and exposed them to important written resources to aid their conceptual understanding. This should happen at the end of a unit, but it can also happen at other times when you are trying to get students to talk about evidence.
Because all students in your classes are learning the language of science, they will need help constructing a gapless and rich causal explanation. Your English language learners in particular can benefit from special forms of scaffolding. Click here to see a strategy that uses sentence-starters and key words to support everyone's attempts at explanation.
If you would like to see examples of this discourse in action, you can go to the following case pages:
- Janet teaching about fungi to middle school students
- Melissa teaching about forces and motion to middle school students
- Brian teaching the physics of sound to high school students
- Bethany teaching about the Gas Laws to high school students