Welcome to Assessing Explanations!
Have you ever heard a friend give a really wild excuse for why they were late? Maybe they said a dragon blocked the road, or perhaps they simply said the bus was late. You probably didn't believe the dragon story, but you might have believed the bus story. In Thinking Skills, we do the exact same thing: we look at evidence and decide if the explanation given for it actually makes sense. This chapter will show you how to be a professional "excuse-checker" for the A Level exam!
1. What is an "Explanation for Evidence"?
In the "Evaluating Evidence" section of your syllabus, an explanation is a statement that accounts for why or how something happened. It is different from an argument because it isn't trying to persuade you to believe a new claim; instead, it is trying to clarify the cause of a fact we already know is true.
Example:
Evidence: The school field is soaking wet.
Explanation: It rained heavily for three hours last night.
Don't worry if this seems simple! The challenge in the exam is deciding whether the explanation provided is the best one or if it is weak.
2. How to Assess an Explanation
When you are asked to assess (make an informed judgement) an explanation in Paper 2 or Paper 4, you should look at three main areas. You can remember these with the "P.A.C." check:
P – Plausibility
Plausibility asks: "How likely is this explanation to be true in the real world?" If an explanation relies on something extremely rare or impossible, it has low plausibility.
Tip: A plausible explanation fits with our general knowledge of how the world works.
A – Alternative Explanations
This is the most important skill! Even if an explanation is possible, is there another reason that makes more sense? If you can find a better alternative, the original explanation becomes weaker.
Example: If a student’s grades drop, the teacher might explain it as "laziness." However, an alternative explanation could be that the student has been ill or has problems at home.
C – Consistency
Does the explanation fit with all the other evidence we have? If an explanation explains one piece of evidence but contradicts another, it is a poor explanation.
Reference: This links to Section 5.1.1 (Consistency with other evidence). If the facts don't line up, the explanation fails the test.
Quick Review: An explanation is strong if it is plausible, matches all consistent evidence, and isn't easily replaced by a better alternative.
3. Real-World Application: The Case of the Missing Cookies
Imagine you find an empty cookie jar on the counter. Your younger brother says: "A ghost came in and ate them all!"
Let's assess his explanation:
1. Plausibility: Very low. We have no scientific evidence that ghosts eat cookies.
2. Consistency: If you see chocolate crumbs on your brother's shirt, his "ghost" explanation is inconsistent with the physical evidence.
3. Alternative: A much more likely alternative is that your brother ate them!
Key Takeaway: When you see an explanation in a Document (Paper 4) or Source (Paper 2), always ask: "What else could have caused this?"
4. Common Mistakes to Avoid
- Confusing Explanation with Argument: In an argument, the author wants you to agree with a conclusion. In an explanation, the author is just telling you why a fact exists. Focus on the "why."
- Ignoring the "How": Sometimes an explanation describes how something happened but fails to explain why. Make sure the explanation actually covers the evidence provided.
- Being too cynical: Don't reject an explanation just because you don't like it. Assess it based on the evidence provided in the exam documents, not just your personal opinion.
5. Step-by-Step: Assessing Explanations in the Exam
When you encounter a question asking you to evaluate or assess an explanation, follow these steps:
Step 1: Identify the Evidence. What is the specific fact that needs explaining? (e.g., "The crime rate dropped by \(10\%\)").
Step 2: Identify the Given Explanation. What reason does the document give? (e.g., "The new street lights scared away criminals").
Step 3: Look for Weaknesses.
- Is it plausible? (Do lights really stop all crime?)
- Is it consistent? (Did crime also drop in areas without new lights?)
- Is there an alternative? (Maybe the police increased patrols at the same time?)
Step 4: Formulate your Judgment. State clearly whether the explanation is strong, weak, or "insufficient" (not enough information to be sure).
Summary Table: Assessing Explanations
| Criteria | What to ask yourself |
| Plausibility | Is this explanation likely to be true in normal life? |
| Consistency | Does it clash with any other facts in the sources? |
| Alternatives | Is there a simpler or more likely reason for this happening? |
| Significance | Does this explanation account for the whole event or just a tiny part? |
Remember: In Paper 2 and Paper 4, you are often asked to suggest your own explanations as well (Topic 5.2.2). The better you are at assessing them, the better you will be at suggesting them!