4. Evidence, Claims, and Limits

Evidence supports a claim only as far as the data reaches. If a study tested one chemical on one bacteria species at one temperature, its conclusion should stay within those conditions.

Strong conclusions use careful language: "increased," "decreased," "was associated with," "under these conditions," or "in this sample." Weak or overreaching conclusions use words such as always, never, proves, all, or none when the data is limited.

Correlation and causation are especially important. A controlled experiment can support a cause-and-effect claim because it changes one variable and measures the response. Observational data can show a pattern, but it usually cannot prove the cause by itself.

When answer choices are close, choose the one that is most directly supported by the evidence and least exaggerated. That is often the GED®'s favorite reasoning move.