chapter 7

Question 1

Scenario : a researcher wants to observe Taylor Swift fans. He decides to look at 500 people, amongst millions. Which is the sample and which is the population?

Answer 1

The sample is the 500 people, the population is millions.

Question 2

How is a census different from a sample?

Answer 2

While a sample is a portion of the population, a census aims to collect data from every person of the population.

Question 3

When can a sample be biased?

Answer 3

When using convenient sampling and self-selection.

Question 4

What are the 6 types of probability sampling?

Answer 4

1. simple random sampling (names in a hat)
2. systematic sampling (rolling a dice, picking ever x person in a list)
3. cluster sampling (finding existing groups of ppl and randomly selecting some groups)
4. multistage sampling (existing groups, choose some and randomly select x from each)
   5 stratified random sampling (particular characteristic – specific demographic)
5. oversampling (overrepresents one or more groups)

Question 5

While random sampling increases ___ validity, random assignment increases ___ validity

Answer 5

external ; internal

Question 6

What are the 4 nonprobability sampling techniques?

Answer 6

1. Convenience sample
2. Purposive sampling (targeting a group of interest)
3. Snowball sampling (asking participants to recruit others)
4. Quota sampling (certain # of people with specific characteristic)

Question 7

True or false : sampling technique, not sample size, determines external validity

Answer 7

True : the estimate only becomes more precise, not more valid.