Explain how to create a claim. If students are going to create their own claims, be sure to provide a variety of examples unrelated to their topic so that students understand how claims should be written—without providing ones that they can simply copy as their own. Be sure that the claims directly answer the prompt.
Make it clear to your students that they shouldn’t include “evidence” within the claim. For example, “High school students should be allowed to vote because they know the most about current events,” would not be an appropriate claim because it makes the claim too narrow to include all the available evidence. Similarly, a claim should not be so broad or weak that either it doesn’t answer the prompt or it makes gathering effective evidence difficult. For example, “The voting age is wrong,” does not specifically answer the prompt and is not a very strong claim that needs to be proven. The best claims require digging into evidence to determine whether or not they are true or valid.
Discuss how to rate evidence quality.
How reliable is the evidence? As students develop their case, it’s important for them to rate the quality of the evidence and discuss the decision-making process leading to that rating. Try using a rubric to help students determine which evidence deserves a four- or five-star rating. Ask them to explain what they think a one-, two-, or three-star rating would mean. For instance, a one-star rating may indicate that the evidence is simply someone’s opinion; a five-star rating may mean that the evidence source is a scientific journal article with well-documented research.
You can create the rubric ahead of time. Better yet, create one with your students as you discuss different types of evidence they might encounter. Remind students that the initial rating of the evidence is only looking at the reliability of the source and the quality of the evidence overall. This is not the time to evaluate whether or not it supports the claim. Think of the Evidence Bin as a set of impartial facts to be considered; only when they are dragged across to the claim are they considered as supporting or opposing evidence.
Here is a piece of evidence for a claim about what has caused an illness. Note that the rating rationale does not address whether the evidence supports the claim; it only addresses whether the evidence comes from a reliable source.
Discuss the rating of whether the evidence supports or opposes the claim. How important is the evidence to proving or disproving the claim?
When a piece of evidence is dragged to the supporting (green) area of the claim or the opposing (red) area of the claim, students have the opportunity to rate how strongly the evidence supports or opposes the claim. Discuss what the number of plusses or minuses would mean. For instance, a single plus mark may mean that the evidence is not significant or that it has little effect on the determination of whether the claim is true or valid. Evidence rated with five negative marks would mean that the evidence very strongly opposes the claim.
When the example evidence is linked to the supporting area of the claim, students then indicate how well the fact that radon comes from rock/soil supports the claim that radon caused the illness. Explain to your students that the support area is where they describe the strength to which the evidence supports or weakens the claim.
Discuss modifying and evaluating the claim.
What should students do if they find that the evidence they collected does not match their claim? Should they revise their claim, simply show that their claim is refuted, or create a new claim? Clarify what students should do as they come closer to a conclusion about their claim.
Students also need to know how to evaluate the claim once they have completed gathering and evaluating their evidence. Discuss how to review the evidence quality in relation to whether it supports the claim. Ask students to think about:
Discuss a variety of “what if’s” to help students understand that evaluating complex issues is rarely black and white.