SAT Reading: Command of Evidence – Textual (Scientific)

🔬 What Are These Questions?

These questions ask you to find the sentence or part of a scientific passage that best supports a claim, interpretation, or the answer to a previous question. You'll often deal with topics like biology, physics, environment, or data-heavy arguments.

🎯 What They Test

Identifying relevant scientific evidence.
Matching data, hypotheses, or conclusions with supporting statements.
Analyzing how studies, observations, or facts are described.

🧠 How to Approach

1. Solve the Main Question First: Don’t look at the evidence question until you’ve confidently answered the interpretation question.
2. Look for Direct Support: Find the sentence or phrase that clearly proves the point — not just related facts or general ideas.
3. Match Key Concepts or Data: Look for numbers, conditions, results, or phrases that back the claim.
4. Avoid Distractors: Eliminate evidence that sounds scientific but doesn't directly support the answer.

📖 Example (Scientific Passage)

“In a controlled experiment, researchers exposed Plant A to red light and Plant B to blue light for 14 days. They measured chlorophyll production and noted that Plant B produced 35% more chlorophyll than Plant A.”

Q1: What does the experiment suggest about the effect of blue light on chlorophyll production?

A) Blue light reduces plant growth.
B) Blue light has no measurable effect.
C) Blue light increases chlorophyll production.
D) Blue light increases soil moisture.

Q2 (Evidence): Which sentence from the passage best supports the answer to the previous question?

A) “In a controlled experiment…”
B) “Researchers exposed Plant A to red light...”
C) “Plant B produced 35% more chlorophyll than Plant A.”
D) “They measured chlorophyll production...”

⚠️ Common Traps

Choosing a sentence that describes the experiment but doesn't support the conclusion.
Picking a detail that relates to the topic but doesn't prove the answer.
Going for a general statement when a specific result is needed.

✅ Practice Tips

Always read the passage with a question in mind: “What’s the result?” or “What’s the claim?”
Underline or highlight result-based or data-driven statements.
Use practice tests (Bluebook or Khan Academy) with science-based texts.