1. Evaluating a Statistical Article
L I – To build up the skills required to critically analyze and evaluate a statistical report.

2. Features of a Stat. Article
Read the article about driving habits.
Working with a partner and using the sheet provided write down the main features of the article. (Both of you should have a copy of the information) – 15 mins
We will discuss your answers as a class.

3. 500

4. Not eligible for survey
Selection Bias: Population sampled is not exactly the population of interest.
Target population (e.g. adults in NZ)
Sampling frame (e.g. households with a landline phone)
Not included in sampling frame
Cannot be contacted
SAMPLED POPULATION
Not eligible for survey
Refuse to respond
Incapable of responding

5. Write a report Who carried it out and who funded it
A report on a sample survey/poll should include:
Who carried it out and who funded it
target population (population of interest)
sample selection method
the sample size and the margin of error
the date of the survey
the exact question(s) being asked
the results
the claims (inferences) made

6. Evaluating a Statistical Article
L I – To build up the skills required to critically analyze and evaluate a statistical report.

7. Evaluation of a Statistical Article
Read the article about raising money for extra transport spending.
Use the worry questions sheet to try and help you pick out the information required in the table.
The more information you can identify at this stage the easier it will be to write your report.
Feel free to discuss your findings with others at this stage.
Note: You can now include non sampling errors and margin of error calculations in your analysis.

8. Your report must include:
Introduction. Brief summary of the article detailing who carried it out, the date published and who funded it? Potential bias?
target population (population of interest) and who was sampled. Do these match up well? What method was used? Was the sample selection method well chosen?
the sample size and the margin of error. Try to explain what the margin of error means by providing a range.
the question(s) being asked with the results. Are the results relevant to the article? Are the questions fair? Are graphs/tables fair/misleading? Any non-sampling errors?
What claims (inferences) are made? Are they fair? Can the claims be verified? Is the conclusion of the report accurate?
Any missing information? Discuss how this affects the overall validity of the report. Does it make it more/less believable?