How scientific investigation practice works
Each page in this series holds one topic from the ACT Science test. The list on the left shows every question in the pool; the number tile turns green once you have checked a question, and a saved question is easy to find again with the Bookmarked filter.
- Pick a question. Use the list, the search box or the difficulty filter, or just press Next question to go in order.
- Answer it. One question at a time from a scientific passage with data, an experiment or competing explanations.
- Check your answer. Your result shows every choice marked, your pick, the correct option and a short explanation of why.
- Try it again or move on. A question you got wrong is worth a second attempt after you have read the explanation.
Prefer a short set with a score at the end? Build a scientific investigation set of 5, 10 or 20 questions, timed or untimed.
What scientific investigation covers on the ACT
On the ACT Science test, Scientific Investigation questions map to Scientific Investigation. Our practice results show raw accuracy for this category so you can identify a skill to revisit. Official ACT reports use their own scoring method.
How to approach scientific investigation
Separate the independent variable, the measured outcome and the conditions kept constant. To predict a result, use the pattern in the experimental data rather than a guess about the topic.
Before you move on: When comparing studies, check that their conditions are comparable before drawing a conclusion.
The 50 questions here cover 28 skills, including:
- Identify the independent variable
- Purpose of a step
- Identify a controlled variable
- Choose the next trials
- Purpose of a controlled variable
- Purpose of repeated trials
- Design an experiment to test a hypothesis
- Identify the independent variables
- Comparison that isolates one variable
- Effect of a procedure change
- Purpose of a control group
- Identify the dependent variable
This pool has 16 questions labelled easy, 17 medium and 17 hard by our team. These are practice labels, not official ACT difficulty ratings. Filter when you want to warm up or stretch. All 50 questions are available to practice.
Tips for scientific investigation questions
- Read the question first, then find the one table, graph or paragraph it points to. Most questions use a single source.
- Trace values with your finger or a straight edge to avoid misreading a row or an axis.
- Watch the direction of a trend: as one variable goes up, does the other rise, fall or stay flat?
- For conflicting viewpoints, decide what each scientist claims before you answer any question about them.