Sampling Methods

Question 1

What is a census?

Answer 1

Measures every member of a population

Question 2

What is an advantage of a census?

Answer 2

Results should be completely accurate

Question 3

What are the disadvantages of a census?

Answer 3

•Time consuming and expensive
•Large data is hard to process

Question 4

What is a sample?

Answer 4

A selection of observations taken from a subset of the population

Question 5

What are the advantages of a sample?

Answer 5

•Less time consuming and cheaper
•Fewer people and less data

Question 6

What are the disadvantages of a sample?

Answer 6

•Data may not be accurate
•Sample may not be large enough to give information

Question 7

What is random sampling ?

Answer 7

Each member of the population has an equal chance of being selected

Question 8

What is simple random sampling?

Answer 8

Each member of the population has equal chance of being selected

Question 9

What are the advantages of simple random sampling ?

Answer 9

•Free of bias
•East and cheap for small samples

Question 10

What are the disadvantages of simple random sampling?

Answer 10

•Sampling frame needed
•Not suitable for large samples

Question 11

What is systematic sampling?

Answer 11

The required elements are chosen at regular intervals from an ordered list

Question 12

What are the advantages of systematic sampling?

Answer 12

•Simple and quick to use
•Suitable for large samples and populations

Question 13

What are the disadvantages of systematic sampling?

Answer 13

•A sampling frame is needed
•Bias introduced if the sampling frame is not random

Question 14

What is stratified sampling?

Answer 14

The population is divided into mutually exclusive strata and a random sample is taken from each

Question 15

What are the advantages of stratified sampling?

Answer 15

•Sample accurately reflects population structure
•Proportional representation of group

Question 16

What are the disadvantages of stratified sampling?

Answer 16

•Population must be clearly classified into distinct strata
•Not suitable for large stratum

Question 17

What are the three types of random sampling ?

Answer 17

•Simple Random Sampling
•Systemic Sampling
•Stratified Sampling

Question 18

What are the two types of non-random sampling?

Answer 18

•Quota Sampling
•Opportunity Sampling

Question 19

What is quota sampling?

Answer 19

An interviewer or researcher selects a sample that reflects the characteristics of the whole population

Question 20

What are the advantages of quota sampling ?

Answer 20

•No sampling frame required
•Allows a small sample to be representative of the whole population

Question 21

What is opportunity sampling?

Answer 21

Sample is taken from people who are available at the time of study

Question 22

What are the advantages of opportunity sampling?

Answer 22

Easy and inexpensive

Question 23

What are the disadvantages of opportunity sampling?

Answer 23

•Unlikely to provide a representative result
•Highly dependent on individual researcher

Question 24

What is a continuous variable?

Answer 24

A variable that can be any value within a given range

Question 25

What is a discrete variable?

Answer 25

A variable that can only be specific values

Question 26

What is quantitative data?

Answer 26

Data associated with numerical observations

Question 27

What is qualitative data?

Answer 27

Data associated with non-numerical observations