1. Unit 5 Notebook
Pages 31 -

2. Page 31 – Errors in Sampling
Sampling errors are errors caused by the act of taking a sample. They cause sample results to be different from the results of a census

3. Page 32 – Random Sampling Error
The deviation between the sample statistic and the population parameter caused by chance in selecting a random sample. T he margin of error in a confidence statement includes only random sampling error

4. Page 33 – Nonsampling Errors
Errors not related to the act of selecting a sample from the population. They can even be present in a census

6. Page 34 – Other Vocabulary
Sampling Frame – the list of individuals from which we will draw our sample
Undercoverage – this occurs when some groups in the population are left out of the process of choosing a sample
Processing errors – mistakes in mechanical tasks such as arithmetic or data entry

7. Page 34 – Other Vocabulary
Response error – when someone gives you an incorrect response
Nonresponse error – when information cannot be collected from an individual selected for a sample
Wording bias – when the wording of a question affects the responses

8. A few words make a big difference…
How do Americans feel about government help for the poor?
Only 13% think we are spending too much on “assistance to the poor” but 44% think we are spending too much on “welfare”
It seems that “assistance to the poor” s nice and hopeful but “welfare” is a negative word – small change, big difference!

12. Page 35 – Types of Samples Stratified Random Sample
Divide the sampling frame into groups called strata (i.e. 9th grade, 10th grade)
Take a SRS from each strata
Probability Sample – a sample chosen by chance
Systematic Sample – where a sample is chosen by a pattern (i.e. every 10th person)
Simple Random Sample - SRS