Planning and Refining an Investigation
Plan and conduct statistical investigations by posing and refining questions or identifying a problem and collecting relevant data; analyse and interpret the data and communicate findings within the context of the investigation.
Read this first
Ask, collect, display, interpret, report. If the question is vague, fix it before you start.
Grouping the data makes the shape easier to see.
Words you need
- Refine
- Improve a question so it can be answered.
- Interpret
- Say what the data means.
- Findings
- What you learned from the data.
Worked example
e.g. Investigate how much sport your class plays.
- First draft the question. How much sport do you play?
- That is too vague. Refine it. How many hours of sport do you play each week?
- Collect the answers, then group them into ranges.
- Most children play 1 to 2 hours.
- Report the finding, and say you only asked one class.
Refine the question before you collect. Afterwards it is too late.
Practice
The pictures fade as you go. By the last few you are on your own.
1Which group is the most common?with a picture
Answer1 to 2 hours.
2How many children were asked?with a picture
Answer25.
3Refine this: do you like reading?with a hint
Need a hint?
Make it something you can count.
AnswerHow many books did you read last month?
4Why group data into ranges?with a hint
Need a hint?
What happens with lots of different values?
AnswerIt makes the shape clearer.
5Name the five steps of an investigation.on your own
AnswerAsk, collect, display, interpret, report.
6You surveyed your class. Can you speak for the school?on your own
AnswerNo. One class is not enough.
7What must a report always state?on your own
AnswerThe finding, and who was asked.
Think about it
1
Why refine a question?
One good answerA vague question gives answers you cannot use.
2
When should you group data?
One good answerWhen there are too many different values to show separately.
Common mistakes
Collecting first and thinking later.
Get the question right before you start.
Claiming your finding is true for everyone.
It is only true for the group you asked.