In the AP Environmental Science exam, one of the three Free-Response Questions (FRQs) is almost always an experimental design prompt. These questions test your ability to apply environmental science concepts to a practical investigation scenario—something College Board loves because it blends critical thinking, data analysis, and scientific reasoning.
This RevisionDojo guide walks you through:
- What the experimental design FRQ looks like
- How to structure your response for maximum points
- Practice examples with breakdowns
- Common pitfalls and how to avoid them
1. Understanding the Experimental Design FRQ
An APES experimental design FRQ typically asks you to:
- Propose a hypothesis.
- Outline an experimental setup.
- Identify independent, dependent, and controlled variables.
- Explain methods for data collection.
- Suggest statistical analysis techniques.
- Interpret potential results.
Example prompt:
A scientist is testing the effect of different nitrogen fertilizer levels on algae growth in a pond ecosystem. Design a controlled experiment to determine the impact of nitrogen concentration on algae biomass.
2. How to Structure Your Answer
Step 1 – Restate the Problem & Hypothesis
- Write a clear, testable hypothesis in an “If…then…” format.
- Example: If nitrogen concentration increases, then algae biomass will increase due to higher nutrient availability.
