Week 5 Textbook Chapter 4

Question 1

How is a target population defined?

Answer 1

Through inclusion and exclusion criteria.

Question 2

What is the difference between probability and non probability sampling?

Answer 2

Random selection

Question 3

What do sample statistics do?

Answer 3

Estimate populations parameters of characteristics, processes and behaviours.

Question 4

What are sampling frames? Use?

Answer 4

List all elements in the target populations. Used to select cases.

Question 5

What are the two types of sampling errors?

Answer 5

1) random sampling error 2) systematic sampling error

Question 6

What does CLT stand for?

Answer 6

Central Limit Theorem

Question 7

What is the EPSEM principle?

Answer 7

Each element in the target population has a known, equal and nonzero probability of selection.

Question 8

What are the benefits of random selection?

Answer 8

1) Increases representativeness 2) Improves generalisability of findings

Question 9

Probability sampling: simple random sampling?

Answer 9

Uses a lottery or random number table method to select elements numbered sequentially.

Question 10

Probability sampling: systematic random sampling?

Answer 10

Uses a sampling ratio, interval and random start to select every kth element in the sampling frame.

Question 11

Probability sampling: stratified random sampling?

Answer 11

Divides the target population into strata based on 1) key characteristics 2) an equal number of elements are selected from each stratum

Question 12

What is the difference between Proportionate and Disproportionate stratified random sampling?

Answer 12

Use different sampling fractions to resemble (proportionate) or differ (disproportionate) from the proportion fond in the target population.

Question 13

How does cluster sampling work?

Answer 13

Randomly selects naturally groups (clusters) and elements within the chosen clusters.

Question 14

PPS Cluster sampling?

Answer 14

Clusters are selected based on the number of elements in each one.

Question 15

Non-probability Sampling: Convenience sampling?

Answer 15

Chooses samples based on their accessibility.

Question 16

Non-probability Sampling: Purposive Sampling?

Answer 16

Uses researchers knowledge and judgment to select cases.

Question 17

Non-probability Sampling: Quota Sampling?

Answer 17

Select cases based on characteristics proportionate to what exists in the population.

Question 18

Non-probability Sampling: Snowball Sampling?

Answer 18

Uses informants to make referrals to the next participant.

Question 19

What determines sampling error?

Answer 19

1) heterogeneity of the population 2) sample size 3) confidence level

Question 20

What is a confidence level?

Answer 20

Indicator of the probability that the true population parameter lies within the confidence interval values (two set–high and low)

Question 21

Standard Error?

Answer 21

Calculates the standard deviation value (shows how well the sample mean estimates the population mean).

Question 22

How to reduce sampling error generally?

Answer 22

Get a larger sample.

Question 23

When is a large sample required generally?

Answer 23

1) heterogeneous populations 2) higher confidence levels (if comparing subgroups) 3) when there are a large numbers of variables

Question 24

What are the ethical considerations of sampling?

Answer 24

1) voluntary and informed consent 2) take care with vulnerable populations 3) guarantee anonymity 4) be transparent when reporting results