The Problem: Reasoning is Hard for Students (and Grown-ups)
If you’ve been teaching the Claim – Evidence – Reasoning structure of arguments, then you’ve probably discovered that the Reasoning is the toughest part of an argument for students to understand and construct. They are pretty good with making a claim and listing evidence that supports the claim…but how to reason why, or in what ways does the evidence support the claim? That’s where people of all ages often get stuck. For example, a middle school science student might argue about kitchen chemistry…
Claim & Evidence:“When I mix vinegar and baking soda in a sealed baggie, new substances are formed, but the total amount of matter stays the same. I weighed the ingredients before mixing, and I weighed the new substances after the reaction, and the masses were the same.”
Reasoning: “What do you mean that’s not enough of an argument? What else is there to say? The mass stayed the same…end of story.”
As the teacher, how can I coach this student to understand what “reasoning” is all about? Is there an all-purpose-rule-of-thumb-for-reasoning that can be used in all arguments? Or, are there different kinds of reasoning that can be applied in certain situations?
A Solution Tool: NGSS Crosscutting Concepts
The solution method I’m proposing will make authentic, powerful use of the NGSS “Crosscutting Concepts,” which are sometimes considered a lesser dimension of NGSS. I have found myself thinking, “Golly, it’s not such an important dimension as the other two (Science & Engineering Practices or the Disciplinary Core Ideas).”…or…”Jeepers, I can’t handle all three dimensions yet, so I’ll just put the Crosscutting Concepts on hold until later…maybe much later.” Surprisingly, later has come sooner rather than later for me, because the Crosscutting Concepts so nicely support the Claim-Evidence-Reasoning structure.
What are the Crosscutting Concepts? All seven of them are listed below, with micro-blurbs. See if you agree with me that these describe ways of reasoning about phenomena that we are trying to explain, and they also describe ways of thinking about problems that we are trying to solve.
- Patterns—Observing patterns of shape, arrangement, data, and events guides their organization, and prompts questions about influential factors.
- Cause and effect—Explaining causal relationships and their mechanisms.
- Scale, proportion, and quantity—Recognizing connections across differences in size, time, and energy.
- Systems and system models—Defining and modeling the system under study (boundaries, parts, interactions) provides tools for generating and testing explanations and solutions.
- Energy and matter—Tracking Flows, cycles, and conservation of energy and matter into, out of, and within systems.
- Structure and function—An object’s shape and substructure can help identify its properties and functions.
- Stability and change—For natural and built systems alike, conditions of stability and determinants of rates of change or evolution of a system are critical elements of study.
Shoring Up the Kitchen Chemistry Reasoning
Let’s take another look at the middle schooler’s argument, and see if a little coaching can help.
Claim & Evidence: “When I mix vinegar and baking soda in a sealed baggie, new substances are formed, but the total amount of matter stays the same. I weighed the ingredients before mixing, and I weighed the new substances after the reaction, and the masses were the same.”
Coaching better student Reasoning: OK, I tell my student that the Claim identified a powerful scientific principle known as Conservation of Matter (even when changes occur, matter cannot be created or destroyed). I ask my student, “Why doesn’t the amount of matter change?” My student says it might have something to do with matter being made of atoms. I say, “That’s right, so your Reasoning should focus on ‘energy & matter.’ Where does the matter come from, and where does it go?” I know that I’m suggesting that my student use Crosscutting Concept #5, energy & matter, which in this situation is the type of reasoning that can support the argument. If I’m really on my game, I’ve got a wall chart of the Crosscutting Concepts, and I’m pointing to it as we speak.
Upgraded energy & matter Reasoning: The student’s revised reasoning might sound like, “The vinegar and baking soda molecules are made of atoms. Those atoms get rearranged into new molecules, but they do not disappear, and no new atoms will suddenly appear, either. That’s why the new substances weighed exactly the same as the vinegar and baking soda.”
Stay Tuned for Lesson Plans
Tomorrow I’ll share two lesson plans that each use the Crosscutting Concepts twice to help students understand, identify, and use specific types of reasoning.