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Collecting Data - A personal investigation


A personal investigation, commonly called an interview, is a method for collecting data. They are useful because interviewers can get more information from participants than if they just answered a survey because interviewers can ask follow-up question and get the story behind a person's answer.


Should Bikes be Registered?

There has been some discussion in the news that bicycles should have to pay registration fees if riders wish to use roads with cars. Mathspace decided to interview people about whether or not they thought this was a good idea.

1. Design the interview questions

Good interview questions should be unbiased, neutral and open-ended. In addition to questions about registering bikes, we made sure we collected some information about the people we were interviewing- their age, whether or not they own a bike, whether or not they own a car etc.

We decided not to include this question in the personal investigation.

"Most people think that cyclists should have to pay to use the roads just like cars do. Do you agree?"

Question: Why may we have chosen to not ask people this question?


2. Decide who to interview

We want to make sure that the people we interview are representative of the whole population. So we made sure we interviewed people who regularly cycled to work, people who campaigned to have bikes registered as vehicles, as well as a random sample of people who weren't biased one way or the other.

Question: Why would interviewing people who are obviously for/ against registering bikes be useful?


3. Conduct the interview

Interviews should be conducted in a neutral setting. Questions should be asked one at a time and the interviewer should remain neutral (just like the questions you spent so long writing). Also, make sure you record the interview or take notes while it is going on.

Question: Can you think of any situations that may happen during an interview that would not help you answer your research question? What strategies could you use to avoid these situations?


Now it's your turn: Work in Groups

1. Choose a topic and research question (e.g. the environment, a school issue, water safety) and design a set of interview questions.

2. Decide who you are going to interview- teachers, parents, students, the principal.

3. Conduct the interviews. Each member of the group should aim to interview around 5 people each.

4. Write a report about what you learned from your interviews.



Conduct investigations using the statistical enquiry cycle: – gathering, sorting, and displaying multivariate category and wholenumber data and simple time-series data to answer questions;– identifying patterns and trends in context, within and between data sets; – communicating findings, using data displays

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