The current ACT Science section is an optional 40-minute, 40-question add-on.

Science does not enter the current ACT Composite, which is based on English, Math, and Reading.

If you take Science, ACT measures how well you can interpret data, reason about experiments, and evaluate scientific explanations.

It is not primarily a memorization test. For the full rundown of the current test format and how each section is weighted, see our Enhanced ACT guide.

Current Science categories

ACT's current student-facing blueprint gives approximate ranges:

• Interpretation of Data: 38–50%
• Scientific Investigation: 18–32%
• Evaluating Scientific Arguments and Models with Evidence: 24–38%

ACT also describes three common information formats:

• Data Representation
• Research Summaries
• Conflicting Viewpoints

Important: no calculator

ACT states that calculators are not permitted on the Science section.

Fortunately, the arithmetic is generally designed to be manageable without one.

Skill 1: locate data

Start with:

• graph title;
• axes;
• units;
• legend.

Do not read a graph as a picture.

Read it as a coordinate system.

If x-axis = temperature and y-axis = reaction rate, know which variable you are comparing before reading values. For deeper practice reading tables and graphs, see our ACT Science data and graphs guide.

Skill 2: identify trends

Common patterns:

• increases as x increases;
• decreases as x increases;
• rises then falls;
• plateaus;
• no clear relationship.

Do not overstate.

If the values fluctuate, “generally increases” may be more accurate than “always increases.”

Skill 3: interpolate

Interpolation means estimate within the measured range.

If:

• 20°C → 10 units
• 30°C → 20 units

then at 25°C, a linear estimate might be around 15 units.

Skill 4: extrapolate

Extrapolation predicts outside the measured range.

It is less certain.

A question may ask what would happen if the trend continued.

Do not assume a trend must continue forever in real life; answer within the model/question.

Research Summaries

These describe one or more experiments.

Track:

• independent variable;
• dependent variable;
• constants;
• control group;
• procedures;
• results.

Independent variable

What researchers change.

Example:

Plants receive 0, 5, or 10 grams of fertilizer.

Independent variable: fertilizer amount.

Dependent variable

What researchers measure.

Example:

Plant height after 30 days.

Dependent variable: height.

Control

A comparison condition.

If one group receives no treatment, that group may serve as a control.

But do not assume every experiment has a control group unless described.

Why repeat trials?

Repeated measurements can:

• reduce influence of random variation;
• improve reliability;
• estimate variability.

Conflicting Viewpoints

These passages give multiple explanations.

Your job is not to decide which scientist is “right” based on your opinion.

Make a mini-table:

Then answer:

• agreement;
• disagreement;
• response to new evidence.

For more worked examples of this passage type, see our ACT Science conflicting viewpoints guide.

New evidence questions

Ask:

Which viewpoint predicts this result?

Do not reread the entire passage blindly.

Find the exact disagreement and match the new observation.

Outside science knowledge

ACT says advanced science knowledge is not required, though general introductory science background may sometimes be needed.

Use passage/data first.

If a question explicitly requires a basic principle you know, use it.

But do not let outside knowledge override the given model.

Original mini-practice

Experiment:

Researchers tested enzyme activity at three temperatures.

1

Which statement is supported over the tested range?

A. Activity decreases as temperature increases.
B. Activity generally increases as temperature increases.
C. Activity remains constant.
D. Activity is highest at 10°C.

2

If the trend were approximately linear between 20°C and 30°C, activity at 25°C would be closest to:

A. 5
B. 9
C. 14.5
D. 25

3

What is the independent variable?

A. enzyme activity
B. temperature
C. number of researchers
D. table format

Answers

1. B
2. C
3. B

Pacing

40 questions / 40 minutes = 60 seconds per question on average.

But passages and data sets vary.

Bank time on direct data-location questions.

Spend more time on:

• multi-graph synthesis;
• experiment redesign;
• conflicting viewpoints.

Do not spend two minutes calculating something that can be estimated.

High-value question order inside a passage

Often:

1. direct lookup;
2. comparison;
3. trend;
4. inference;
5. experimental reasoning.

Take easy evidence points first.

Common traps

Trap 1: wrong axis

Check units.

Trap 2: confusing independent/dependent variable

Changed vs measured.

Trap 3: assuming causation from graph association

Follow experiment design.

Trap 4: using your science opinion

Use the model provided.

Trap 5: calculator-style overcomputation

Most values can be compared/estimated.

Trap 6: reading every word before looking at the question

For data-heavy sets, the questions often tell you what to inspect.

How to prepare

Practice three separate skills:

Data

Graphs, tables, trends.

Experiments

Variables, controls, procedures.

Viewpoints

Claims, evidence, disagreement.

Then combine them under time pressure. Browse the rest of our ACT guides for section-specific strategies.

Official references

• ACT Science description: https://www.act.org/content/act/en/products-and-services/the-act/test-preparation/description-of-science-test.html
• ACT test overview: https://www.act.org/content/act/en/products-and-services/the-act.html

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