Technical & STEM Writing
Be precise, concise, and consistent. Define key terms, include units, and present data clearly with tables or figures.
Tone
Use objective, precise language. Avoid colourful metaphors in reports: state what you observed and how you measured it.
Passive voice is acceptable when the action is more important than the actor ("the solution was heated to 80°C"), but active voice is often clearer ("we heated the solution to 80°C").
- Passive: "The mass was measured using a balance."
- Active: "We measured the mass using a balance."
Definitions, data, diagrams
Define specialised terms the first time you use them.
Present data with units (cm, g, °C) and consistent decimal places.
Use labelled diagrams or tables if allowed.
Mini glossary
- Accuracy: How close a measurement is to the true value.
- Precision: How repeatable measurements are (consistency).
- Control: A sample or condition kept constant for comparison.
Presenting a small table
Example: Measurements of plant height (cm) after 7 days.
| Light condition | Mean height (cm) | Std. dev. |
|---|---|---|
| Full light | 4.8 | 0.6 |
| Partial shade | 3.2 | 0.4 |
| Dark | 1.0 | 0.2 |
Note: include units and a short caption explaining the table.
Lab report mini‑template
- Title & aim
- Hypothesis
- Method (past tense, numbered)
- Results (table/graph)
- Conclusion (link to hypothesis)
- Evaluation (errors, improvements)
Sample short lab (cress light experiment)
Title: The effect of light on cress seed growth
Aim: To investigate how different light levels affect mean plant height after 7 days.
Method (summary): 3 trays of 10 cress seeds each. Tray A: full light, Tray B: partial shade, Tray C: dark. Watered 5 ml daily. Measured height on day 7.
| Condition | Mean height (cm) |
|---|---|
| Full light | 4.8 |
| Partial shade | 3.2 |
| Dark | 1.0 |
Conclusion: Cress grew taller in full light than in shade or darkness, supporting the hypothesis that light increases growth. Evaluation: Use larger sample sizes and measure more than once to improve precision.
Practice
Write a clear method (4–6 steps) for testing the effect of light on cress growth. Include units and controls.
Describing graphs and trends
When you describe a graph, start with the overall trend (increase/decrease/constant), then give specific figures to support your point (e.g. "from 1.0 cm to 4.8 cm"). Mention axes and units, and avoid overstating what the graph shows.
- Overall trend sentence: "Overall, mean height increased as light increased."
- Supporting figures: "Full light: 4.8 cm; dark: 1.0 cm."
- Comment on variability: "Results show some variation (std. dev. 0.6), so repeatability should be checked."
Basic data analysis notes
Introduce simple measures: mean (average), median (middle value) and range. For classroom data, use mean to summarise central tendency and a simple range or standard deviation to indicate spread.
Common mistakes
- Forgetting units (e.g. writing "4.8" without "cm").
- Mixing up mean and median when discussing averages.
- Claiming causation without control or enough evidence.
Extension activities & teacher notes
Extension: run the experiment twice with larger samples and compare results using mean and range. Teacher note: encourage students to plan repeat measurements and to state limitations in the evaluation.
Assessment rubric (technical writing)
- 4 — Excellent: Accurate method, correct units, clear results table/graph, justified conclusion and thoughtful evaluation.
- 3 — Good: Clear method and results, minor issues with precision or evaluation.
- 2 — Satisfactory: Method and results present but missing some detail or units; weak evaluation.
- 1 — Needs improvement: Incomplete method, missing units, unsupported conclusion.