Introduction: Thinking Like a Detective

Welcome to one of the most exciting parts of the Thinking Skills syllabus! In this chapter, we focus on suggesting an inference from evidence. If "evidence" is the set of footprints left at a crime scene, the "inference" is your realization of which direction the person was walking.

Suggesting an inference is a key skill for Paper 2 and Paper 4. It’s not just about repeating what the evidence says; it’s about figuring out what the evidence means. Don't worry if this seems tricky at first—by the end of these notes, you'll be able to move from raw data to a smart conclusion with confidence.

What is an Inference?

An inference is a conclusion you draw based on evidence and reasoning. It is something that is not explicitly stated in the text, but is supported by the facts provided.

Think of it as a simple equation:
\( Evidence + Reasoning = Inference \)

Example:
Evidence: Every time the local bakery sells "Midnight Chocolate" cake, they sell out within ten minutes of opening.
Inference: The "Midnight Chocolate" cake is very popular with customers.

Notice that the evidence didn't say the word "popular." We inferred it because "selling out quickly" is a strong indicator of popularity.

Step-by-Step: How to Suggest an Inference

When you are asked to "suggest an inference" in an exam, follow these three steps:

1. Identify the Relevant Evidence

Look closely at the data, text, or graphs provided. What are the specific facts? Avoid looking for what you think should be true; look only at what is actually there.

2. Look for the "So What?"

Ask yourself: "If these facts are true, what else is likely to be true?" Look for patterns, trends, or connections between different pieces of evidence.

3. Formulate a Cautious Claim

A good inference doesn't "over-reach." It stays close to the facts. Use "soft" or "modal" language (like might, could, suggests, or likely) to make your inference more robust.

Key Takeaway

An inference is an unspoken truth hidden within the evidence. Your job is to bring it into the light.

"Safe" vs. "Dangerous" Inferences

In Thinking Skills, the best inferences are "safe." A safe inference is one that is highly likely given the evidence. A "dangerous" inference (often called a "leap") goes too far and cannot be proven by the evidence alone.

Scenario: A study shows that students who eat breakfast every day have higher average test scores than those who do not.

A Safe Inference: "There is a correlation between eating breakfast and academic performance." (This stays strictly within what the data shows).
A Dangerous Inference: "Eating breakfast causes students to become smarter." (This is a leap! The evidence shows a link, but it doesn't prove that breakfast is the direct cause of intelligence—there could be other factors like sleep or home environment).

Quick Tip: To keep your inferences safe, avoid using absolute words like "proves," "always," or "certainly." Instead, use words like "indicates," "suggests," or "is consistent with."

Using "Modal" Language

The Cambridge syllabus emphasizes the command word Suggest. This means you are putting forward a proposal or consideration. To do this well, you should use modal verbs. These help you express the level of certainty in your inference.

Try using these phrases in your answers:
- "This suggests that..."
- "It is likely that..."
- "The evidence indicates..."
- "One possible inference is..."

Common Mistakes to Avoid

Even the best students can fall into these traps. Keep an eye out for them:

  • Repeating the Evidence: If the evidence says "Sales rose by 10%," and you write "Inference: Sales went up," you haven't made an inference. You've just paraphrased. An inference would be: "The marketing campaign may have been effective."
  • Bringing in Outside Knowledge: The exam tests your thinking skills, not your general knowledge. Only suggest inferences that can be supported by the provided documents.
  • Confusing Inference with Explanation: While related, an inference is a conclusion drawn from evidence, while an explanation tells us why the evidence exists. (Note: You can learn more about this in the chapter "Suggest explanation for evidence").

Quick Review: Check Your Progress

What is the difference between evidence and an inference?
Evidence is the raw fact; inference is the logical conclusion we draw from that fact.

Why should we use words like "suggests" or "likely"?
To avoid making "dangerous" leaps that the evidence cannot fully prove.

Can an inference be wrong?
Yes. If an inference is contradicted by other evidence in the sources, it is a weak or invalid inference.

Summary of Suggesting Inferences

To suggest a strong inference, you must be a "logical bridge-builder." You take the solid ground of Evidence and build a careful bridge of Reasoning to reach a Conclusion. Keep your bridges short and sturdy, and always check that they are firmly supported by the facts provided in the text.