Chapter 6 - Sampling

Question 1

4 Types of non probability sampling

Answer 1

CONVENIENCE SAMPLING
- sample is drawn to suit the convenience of the researcher

JUDGEMENT SAMPLING
- Researchers use their judgement alone to select best sampling units

QUOTA SAMPLING
- setting quotas of sampling units to interview certain subgroups of the population

SNOWBALL SAMPLING
- used when it’s difficult to identify members of a target population for reasons of sensitivity or confidentiality.
Eg. studies of HIV/AIDS

Question 2

2 Disadvantages of non probability sampling

Answer 2

• Data could be bias

* not possible to measure sampling error

Question 3

SAMPLING ERROR

Answer 3

Difference between actual population parameter and its sample statistic

Question 4

4 PROBABILITY RANDOM SAMPLING

Answer 4

Simple random sampling
- each member in target pop has = chance of being selected.

Systematic random sampling
- used when a sampling frame exists

Stratified random sampling
- when population is assumed to be heterogeneous. Pop is divided into sunsets where they are more or less homogeneous

Cluster random sampling
- when target population can naturally be divided into clusters of similar data

Question 5

Advantages of random sampling

Answer 5

Random sampling reduces selection bias

Sampling error can be calculated

Question 6

Define sampling distribution

Answer 6

Shows the relationship between a sample statistic and its corresponding population parameter.