The idea, step by step
Plan before collecting
Choose a question that can be answered with data, such as How many minutes did each of two groups spend reading yesterday? State who is included, the time period and the variable. Avoid collecting names or sensitive information when they are unnecessary.
Decide how answers will be recorded before you ask. Use the same unit and question for both groups. Record missing answers as missing rather than replacing them with zero; zero means a genuine measured or counted amount.
Check, display and conclude
Inspect the data for mistakes, missing values and mixed units. Ask about a suspicious entry rather than changing it to fit a preferred result. Choose a display that matches the variable, then compare features such as frequencies, range, clusters and mode.
A conclusion should answer the original question and cite numbers. State a limitation, such as one day of records or a small group. A useful next step might repeat the investigation on another day, using the same method.
A common trap
Changing an awkward observation is acceptable if it makes the graph clearer.
Instead: Keep genuine values. Correct an error only when there is evidence it was recorded incorrectly, and explain the correction.
See the thinking
Make the question measurable
Improve Do we read enough? into a question a Year 6 group can investigate.
- Enough is not defined. Choose a quantity and a clear time period.
- Ask the same question to each participant and record minutes.
Report without inventing a cause
Practice reading times are Group A: 10, 10, 15, 15, 20; Group B: 15, 20, 20, 25, 30. Write a supported conclusion.
- A ranges from 10 to 20 minutes, with modes 10 and 15.
- B ranges from 15 to 30 minutes, with mode 20; its recorded times are generally higher.
- These ten records cover one day, so they do not prove a permanent difference or its cause.
Check your understanding
A student leaves the reading-time answer blank. Should it automatically be entered as 0 minutes?
Show answer
No.
Missing is not the same as reporting no reading. Ask for clarification or label the value missing.
Your turn
6 questions · 12 marks · Work at your own pace.
Read the questions online
- Write a data question about how students travel to school.2 marks
- For a comparison of plant heights, choose one unit to use throughout and explain why.2 marks
- A reading record contains 12, 15, blank and 18 minutes. What should happen to the blank entry?2 marks
- Choose a suitable display for favourite sport categories.2 marks
- For 3, 4, 4, 5, 8 library visits, give a supported conclusion using the mode and range.2 marks
- A class measured playground shade on one cloudy morning. Give one limit and one next step.2 marks
Read the worked solutions
Equivalent correct methods earn the corresponding marks. Include units where asked.
- Write a data question about how students travel to school.2 marks
State the group and a clear time.
Record a category such as walk, car, bus or bicycle.
For example: Which travel method did students in our class use to arrive at school today? - For a comparison of plant heights, choose one unit to use throughout and explain why.2 marks
Using one unit prevents a metre value being compared directly with a centimetre value.
For example, centimetres. - A reading record contains 12, 15, blank and 18 minutes. What should happen to the blank entry?2 marks
Do not invent a measurement.
Zero would mean the person actually reported no reading.
Keep it as missing or ask for the value. - Choose a suitable display for favourite sport categories.2 marks
Separate categories need distinct labelled entries or bars.
A continuous line would wrongly suggest intermediate sports.
A column graph or frequency table. - For 3, 4, 4, 5, 8 library visits, give a supported conclusion using the mode and range.2 marks
4 occurs twice.
.
The most common value is 4 visits, and the range is 5 visits. - A class measured playground shade on one cloudy morning. Give one limit and one next step.2 marks
Identify what was not covered.
Choose repeat measurements that address that limitation. Other sensible plans are acceptable.
Limit: one morning may not represent other times or weather. Next step: repeat at agreed times on several days.
Curriculum reference & lesson scope
Australian Curriculum v9.0; SA Mathematics Curriculum 2026
Variable types; comparative displays; mode/range/shape; media claims; investigations.
Official curriculum source ↗