Interpret scientific tables, graphs and diagrams
Translate between representations, compare measurements and keep predictions distinct from observations.
What you will tackle
- Read tables, graphs and scientific diagrams with units
- Translate representations and compare related datasets
- Identify linear/nonlinear trends and maxima/minima
- Interpolate, extrapolate and calculate changes with appropriate qualifications
Read the variables and scale first
A graph's horizontal and vertical axes identify different quantities; an axis may start above zero. Check units, intervals and which line represents which condition. A diagram may encode a process or apparatus rather than numerical scale. Use its labels and arrows instead of assuming that every drawn distance is a measured distance.
A trend has a domain
The original fertiliser dataset shown here has doses 0,5,10,15 mg and mean plant heights 8,12,15,13 cm. It rises then falls, so a single increasing line misrepresents it. Interpolation estimates within the tested range; extrapolation goes beyond it and requires additional assumptions. Measurements do not automatically explain the mechanism.
| Dose (mg) | Height (cm) |
|---|---|
| 0 | 8 |
| 5 | 12 |
| 10 | 15 |
| 15 | 13 |
| Time | A response | B response |
|---|---|---|
| 0 | 4 | 3 |
| 1 | 8 | 6 |
| 2 | 9 | 12 |
Build your notes, then practise
Work on paper before opening an explanation. Guided tasks provide a starting point; independent tasks remove the scaffolding; application tasks ask you to justify a method or interpretation in context.
Guided practice
Guided 1
Using the fertiliser table/graph, find the dose with the greatest measured height and the changes for each 5 mg step. Does every increase in dose increase height?
Show a starting hint
Compare adjacent observations before extending a trend.
Compare with the explained answer
- The maximum measured mean is 15 cm at 10 mg.
- Changes are +4, +3 and −2 cm.
- The last step is a measured counterexample to an always-increasing claim.
Answer / response criteria: 10 mg; +4, +3, −2 cm; no.
Guided 2
Translate the fertiliser table into points on axes labelled dose (mg) and mean height (cm). Join successive observations and explain the shape.
Compare with the explained answer
- Plot (0,8),(5,12),(10,15),(15,13).
- The first two segments rise and the last falls.
- The representation preserves the maximum at 10 mg and does not justify a single rising line through all doses.
Answer / response criteria: The four plotted points form a rising-then-falling sequence; axes and units must be retained.
Independent practice
Independent 1
In another trial, values at 20°C and 30°C are 10 and 16 units. Estimate the value at 25°C under a linear-between-points assumption. Is a prediction at 50°C an interpolation?
Compare with the explained answer
- 25°C is halfway, giving 10 + (16 − 10)/2 = 13.
- This is an estimate based on a stated local linear assumption.
- 50°C is outside the observed interval, so it is extrapolation.
Answer / response criteria: 13 units under the assumption; 50°C is extrapolation.
Independent 2
Compare displayed Experiments A and B at times 0,1,2. A has responses 4,8,9; B has 3,6,12. At which times is A larger? Which experiment has the greater total increase? Translate B into graph points.
Compare with the explained answer
- A is larger at times 0 and 1; B is larger at time 2.
- A rises 5 units and B rises 9 units from first to last.
- B's points are (0,3),(1,6),(2,12).
Answer / response criteria: A larger at 0 and 1; B has greater total increase; B points as listed.
Application practice
Application 1
A passage claims one treatment is best because it gives the largest response at 10 mg. Design a table comparing two treatments at several doses and explain what evidence would be needed for ‘best at every dose’.
Compare with the explained answer
- Use matching doses and the same response measure for both treatments.
- Include replicated measurements and uncertainty where available.
- The universal claim needs comparisons across the stated domain; winning at one dose is insufficient.
Answer / response criteria: A matched dose-by-treatment table with repeated responses; one winning point cannot establish superiority at every dose.
Application 2
A report says Experiment A was better at every time because its response began higher. Use the two datasets and their graph to revise the claim, stating a limitation on mechanism.
Compare with the explained answer
- The claim fails at time 2, where B is 12 and A is 9.
- A began higher but B showed the larger increase and higher final value.
- The measurements alone do not identify why the responses differ.
Answer / response criteria: A was higher initially and at time 1, but B was higher at time 2 and increased more overall; cause is not established.
What can you explain now?
A report says Experiment A was better at every time because its response began higher. Use the two datasets and their graph to revise the claim, stating a limitation on mechanism.
Compare with the explanation
A was higher initially and at time 1, but B was higher at time 2 and increased more overall; cause is not established.
Explain the reasoning before comparing. This review records your self-assessment rather than an official score or mastery decision.
After trying it yourself, choose your next review. This is your self-assessment.
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Source and review status
Coverage follows the named requirements and examples in the 2026–2027 ACT test guide and subject descriptions. That guide explicitly does not list every possible topic. The broader coded College and Career Readiness Standards are also mapped to conceptual teaching and practice; this does not calibrate a learner to a score band. The separate scientific-background context list and reading-complexity rubric have their own stated limits.
Original teaching and explained self-check practice are available. Specialist review and difficulty calibration remain pending. Essays require self-check or teacher review and are not automatically marked or awarded official scores.
Official source specification / guide