Sampling

Question 1

What is opportunity sampling?

Answer 1

Taking people who are simply most available

I.e. The ones who are nearest/easiest to obtain

Question 2

What are strengths of opportunity sampling?

Answer 2

• quick and convenient

- most popular sampling method

Question 3

What are the weaknesses of opportunity sampling?

Answer 3

• sample is unrepresentative of target population as it’s drawn from a specific area
• meaning findings cannot be generalised

Question 4

How would you do opportunity sampling?

Answer 4

Ask people nearby

E.g. Ask the students in your class or people nearby in a shopping centre

Question 5

What is random sampling ?

Answer 5

Every person in target population has an equal chance of being selected by using a statistical method

Question 6

How would you do random sampling ?

Answer 6

By lottery method .

All members of the target population are given a number and placed in a hat

Question 7

What are the strengths of random sampling ?

Answer 7

• free from researcher bias. Researcher had no influence over who is selected

Question 8

What are the weakness of random sampling?

Answer 8

• representation not guaranteed
• limits ability to generalise
• time consuming

Question 9

What is volunteer (self-selected) sampling?

Answer 9

Participants respond to an advertisement to take part in a study

Question 10

How do you do volunteering sampling ?

Answer 10

Advertise

Question 11

What are the strengths of volunteer sampling?

Answer 11

• Participants are willing to do the research

- quick and easy

Question 12

What are the weaknesses of volunteer sampling ?

Answer 12

• generalisation limited due to volunteer bias
• participants may share certain traits e.g. Keen and curious
• people CBA to turn up, and they differ from non-volunteers

Question 13

What is systematic sampling?

Answer 13

Participants are selected using a set ‘pattern’ (sampling frame)

Question 14

How do you do systematic sampling?

Answer 14

Every nth person is selected from a database of target population

Question 15

What are the strengths of systematic sampling?

Answer 15

• unbiased (little chance of it)

- convenient & simple

Question 16

What are the disadvantages of systematic sampling ?

Answer 16

• sampling error

- complete database of population is required (time and effort)

Question 17

What is stratified sampling?

Answer 17

Participants are selected according to their frequency in the target population

Question 18

How do you do stratified sampling?

Answer 18

Subgroups are identified (or she, gender) the relative percentages of the subgroups in the population are reflected in the sample

Question 19

What are the strengths of stratified sampling ?

Answer 19

• reduces selection bias
• characteristics of the target pop are representative
• generalisability more likely than other methods

Question 20

What are disadvantages of stratified sampling?

Answer 20

Subgroups cannot reflect all ways in which people are different

• complete representation is not possible
• each participant must be identified (time and effort)

Question 21

What is selection bias?

Answer 21

Researcher may avoid certain people or places due to uncertainty or uncomfortablity

Question 22

What is the target population

Answer 22

Refers to the entire group of individuals to which researchers are interested in generalising

I.e. Group of doctors, teachers

Question 23

What is a sample?

Answer 23

A group of participants extracted from target population, should be representative