Understand the idea.
Start with an answerable question
A statistical investigation begins with a question that can have different answers. Decide whose answers you need and what each person will record. For a class picnic survey, ask each pupil for one fruit choice so every response has the same meaning.
Use neutral wording that allows people to give their own answers. Give the intended group a fair opportunity to respond, and collect only information the question needs. Report anonymous totals rather than publishing individual pupils' names or private details.
Follow the evidence
After collecting, check the responses and total the counts before making a display. Support a conclusion with numbers: apples have of the votes, more than any other single fruit. Distinguish the leading choice from a choice everyone made.
Keep your conclusion about the people who actually answered. A class survey does not automatically describe every school or explain why pupils made their choices. State limits such as absent pupils, and remember that the same group might answer differently later.
| Fruit | Votes |
|---|---|
| Apples | 8 |
| Bananas | 6 |
| Oranges | 4 |
| Pears | 2 |
See the method in action.
A supported conclusion
What conclusion is supported by the fruit table?
| Fruit | Votes |
|---|---|
| Apples | 8 |
| Bananas | 6 |
| Oranges | 4 |
| Pears | 2 |
Worked solution
- 1
Check how many choices the table records.
Adding all four frequencies gives the number of pupils represented when each pupil contributes one vote.
- 2
Compare apples with each other fruit.
Apples have the greatest individual count, so they are the most popular single choice.
- 3
Check whether everyone chose apples.
Twelve pupils chose another fruit, so the evidence supports 'most popular', not 'chosen by everyone'.
- 4
Limit the conclusion to these respondents.
The table supports a conclusion about these twenty pupils; it contains no responses from other classes or schools.
Apples were the most popular single choice among these 20 pupils.
Improve a plan
Only three close friends are asked whether the school should buy more basketballs. How could the plan be improved?
Worked solution
- 1
Identify whose views the plan could miss.
Three close friends may share interests and leave other classes or pupils with different interests unrepresented.
- 2
Invite a wider, fairly chosen group from different classes.
Including pupils beyond the friendship group gives a wider range of school views a chance to be heard.
- 3
Ask everyone the same neutral question.
Consistent wording avoids steering answers towards buying basketballs or asking different pupils different questions.
- 4
Report which group answered without identifying individuals.
Readers need to know whose views the results describe, while anonymous totals protect personal details.
Use a wider group and a neutral question, and state who answered.
Try it yourself.
Check your understanding
What is wrong with: Don't you agree our amazing new playground is best?
Show answer & reasoning
It encourages a particular answer.
The words 'Don't you agree', 'amazing' and 'best' encourage approval before the pupil answers. A neutral question such as 'Which playground feature do you prefer?' allows a choice without telling the respondent which answer is wanted.
Keep practising
6 worksheet questions · 9 marks
Read the questions online
- Which is statistical: What is ? or How many books did each pupil read last month?1 mark
- Write a neutral question about preferred playground activities.1 mark
- 15 of 25 class members answer because 10 are away. State one limit of the result.1 mark
- Write one conclusion using numbers from the pet table.2 marks
Favourite-pet survey: one choice per student Pet Votes Cat 5 Dog 7 Bird 3 Fish 5 - A favourite-colour survey is graphed for display. Should it list pupils' full names?2 marks
- More birds are observed on Tuesday than Monday. Does this show Tuesdays always have more birds?2 marks
Read the worked solutions
Equivalent correct methods earn the corresponding marks. Include units where asked.
- Which is statistical: What is ? or How many books did each pupil read last month?1 mark
It expects different answers from different pupils.
How many books did each pupil read last month? - Write a neutral question about preferred playground activities.1 mark
Do not suggest that one answer is better.
One example: Which playground activity do you prefer? - 15 of 25 class members answer because 10 are away. State one limit of the result.1 mark
Absent pupils may have different preferences.
It describes the 15 respondents, not necessarily the whole class. - Write one conclusion using numbers from the pet table.2 marks
Favourite-pet survey: one choice per student Pet Votes Cat 5 Dog 7 Bird 3 Fish 5 .
7 is the greatest category frequency.
Dogs were the most popular single choice, with 7 of 20 votes. - A favourite-colour survey is graphed for display. Should it list pupils' full names?2 marks
The question compares colour choices, not individuals.
No. Anonymous category totals are sufficient. - More birds are observed on Tuesday than Monday. Does this show Tuesdays always have more birds?2 marks
Weather, observation time and other conditions may differ.
Collect more comparable observations before making a wider claim.
No. Two observations do not show what happens every Tuesday.
Curriculum reference & lesson scope
Australian Curriculum v9 / SA Curriculum 2026
Data types/validation; mode; suitable displays; line graphs; statistical investigations.
Official curriculum source ↗