1) to Understand Different Ways of Collecting Data
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Collecting Data
Objectives:
1) To understand different ways of collecting data. 2) To know how and why to collect a sample. 3) To know how to choose a sample. 4) To know what questions are biased and to come up with unbiased questions for a survey. 5) To explore surveys and statistics in the media. 6) To understand why statistics are used in the media.
Key Terms:
Population:
Example:
Sample:
Example:
Data:
Example:
Sampling technique:
Examples:
Biased Questions:
Examples: How can we collect data?
To collect data we use SAMPLING TECHNIQUES.
a. Surveys
b. Experiments
c. Measurement/Counting
2) Why do we collect data?
3) Why don’t we collect data from an entire population (ie, from every person in Canada)?
We instead collect data from a sample.
For example, if we wanted to find out how most students get to school in ESDH: a) We would have to ask students from grades ______. b) We would have to ask ______. c) We would have to ask people who live in ______
______4) Surveys must be simple and clear. The questions should be written so that they don’t produce a biased response.
______
______
Example 1: Chris didn’t help out, did he?
Why it isnt’ good: The person asking the question encourages you to agree that Chris didn’t help out.
How can we change this question?
Example 2: What is your favourite food? a) Dirty Pizza b) Fatty Fries c) Spaghetti
Why it isnt’ good:
How can we change this question?
Example 3: How many siblings do you have? a) none b) one c) two d) three
Why it isnt’ good:
How can we change this question?
Example 4: I work in a car manufacturing plant. I want to collect samples to make sure the car breaks are working correctly. I decide to test cars every Friday at 8am.
Why it isnt’ good:
How can we change this sampling? Sampling Questions Practice
1. Which sampling technique would you use to determine each of the following?
Sampling Techniques To Choose From: Survey Experiment Counting/Measuring
a) The popularity of a new TV show b) The concentration of a chemical in the school’s water. c) The need for traffic lights at the intersection by the school. d) The amount of rainfall in Musquodoboit. e) The opinions of voters on crime in Halifax.
2. Examine each survey question. Determine if the question is bias. If it is, improve the wording of the question.
a) Which age range are you in:
Young Middle-aged Old
Bias/Unbias:
New Question:
b) Select your favourite cereal:
Cornflakes Shreddies Frosted Flakes Oatmeal Bias/Unbias:
New Question:
c) Do you agree that math is boring?
Bias/Unbias:
New Question:
d) The price of a school lunch has not increased in 2 years. Do you think the school lunches are good value for money?
Bias/Unbias:
New Question: e) Which is your favourite colour?
Red Green Blue Yellow Orange White
Bias/Unbias:
New Question:
3. Fix the question and/or choices below.
How old are you? 0-5 7-10 11-18 19+
4. You want to determine the popularity among students in Nova Scotia of the following sports on TV: hockey, football, basketball, golf and baseball. a) Who would be in your sample?
b) Choose a sampling technique and explain why it is suitable.
c) Come up with an unbiased question for the sample.
d) Come up with a biased question for the sample.
5. Jessica works for the Body Shop’s manufacturing company. The Body Shop wants to know if its lipstick is made correctly. a) Choose a sampling technique to find this out.
b) When will you test the lipstick so you get a well-rounded sample? 6. Steve works for the RCMP in Middle Musquodoboit. He wants to find the opinion of residents on crime in the area. a) Create an unbiased survey question for him.
b) Create a biased survey question for him.
7. For each population below, write down why the sample would not be representative of the population. Also write down how you could make it more representative.
a) To find the number of cars owned per family in Canada, collect data in Edmonton and Halifax.
What is wrong?
Fix it:
b) To determine the opinions of Canadians about offshore fishing collect data in communities in Newfoundland.
What is wrong?
Fix it:
c) To collect data about the most popular fast-food restaurant in Halifax, ask people at the local McDonalds.
What is wrong?
Fix it:
8. Travis is doing a project for sociology class. He wants to find out people's opinions on lowering the legal drinking age to 18. a. Design an unbiased survey question that Travis could use for his survey.
b. Design a biased survey question that Travis could use for his survey, if he wanted to influence people to be in favour of lowering the legal drinking age.