1. 2.4 Bias in surveys
Is this a biased survey?

2. Assignment Guidelines

3. There isn’t anything wrong with this survey below right?
The Harlem Globetrotters are an exhibition basketball team that combine comedy, athleticism and theater and they often play to raise charity. A survey for adults in the U.S. asked these honest basketball players as to whether the U.S. should invest in community athletic events.

4. Sampling bias
This type of bias occurs when the sampling frame does not reflect the characteristics of the population

5. Ok well there isn’t anything wrong with this survey below right?
Toronto Prep School surveyed its student body by selecting a systematic sample which was asked about whether they support shorter summer holidays and more holidays throughout the school year.
Less than a quarter agreed to complete the survey. Interestingly, the completed surveys showed that students support a shorter break.

6. Non-response bias
This type of bias occurs when particular groups are under-represented in a survey because they choose not to participate
Raise your hands if you agree with this.

7. Anything wrong with this survey below right?
A highway engineer suggests that an economical way to survey traffic speeds on an expressway would be to have the police officers who patrol the highway record the speed of the traffic around them every half hour.

8. Measurement bias
This type of bias occurs when the data-collection method consistently under-estimates or over-estimates a characteristic of the population

9. Response Bias
The type of bias occurs when participants in a survey deliberately give false or misleading answers
Respondents might want to influence the results or they may be afraid to answer sensitive questions honestly

10. Intentional bias – used to manipulate stats in favour of a certain point of view
Unintentional bias – can be introduced if sampling and data collection methods are not chosen carefully
Leading questions – can give suggested answers which causes a bias
Loaded questions – contains wording or information intended to influence respondents’ answers

11. Any bias below?
Can the proposed record level of healthcare expenditures be justified in view of the enormous deficits facing the Canadian people and the pressing social needs that are currently unmet?

12. Homework page 123 #1-3, 6, 8 Quiz tomorrow on 2.1 and 2.3
Assignment #1 due on Monday