5.sampling

Question 1

What is a population ?

Answer 1

A group of people who are the focus of the researchers interest

Question 2

What is a sample ?

Answer 2

A group of people drawn from a target population who take part in a research investigation

Question 3

What is a target population ?

Answer 3

The target population is the total group of individuals from which the sample might be drawn.

Question 4

What is bias in the context of sampling ?

Answer 4

Bias refers to when certain groups may be over or under represented within the sample

Question 5

What is generalisation ?

Answer 5

The extent to which findings and conclusions from a certain investigation can be broadly applied to the population

Question 6

What is a random sample ?

Answer 6

All members of the target population have an equal chance of being selected for the sample

Question 7

What is the method for a random sample ?

Answer 7

1. Complete list of all members of the target population
2. Assign all names on the list a number
3. Sample is generated through the use of a lottery method

Question 8

What is a stratified sample ?

Answer 8

The sample reflects the proportions of people in certain strata within the target population

Question 9

How do you carry out a stratified sample ?

Answer 9

1. Identifies the different strata that make up the population
2. Work out the proportions needed for the sample to be representative
3. Participants that make up each stratum are selected using random sampling

Question 10

What is an opportunity sample ?

Answer 10

When the researcher selects anyone who happens to be willing and available.

Question 11

How do you carry out an opportunity sample ?

Answer 11

The researcher takes the chance to ask whoever is around at the time of their study

Question 12

What is a volunteer sample ?

Answer 12

Involves participants selecting themselves to be a part of the sample

Question 13

How do you carry out a volunteer sample ?

Answer 13

A researcher may place an advert around where their target audience would be and people will volunteer.

Question 14

What are the strengths of a random sample ? (2)

Answer 14

• free from research bias

- should be representative

Question 15

What are the weaknesses of a random sample ? (3)

Answer 15

• difficult and time consuming
• may end up with a sample that is still unrepresentative
• selected participants may refuse to take part

Question 16

What is the purpose of sampling ?

Answer 16

It is very difficult to study every single person in a target population

Question 17

What is systematic sampling ?

Answer 17

When every nth member of the target population is selected

Question 18

How do you carry out a systematic sample ?

Answer 18

1. A sampling system is nominated e.g every 3rd person (May be randomly determined to reduce bias)
2. The researcher then works through the sampling frame until the sample is complete

Question 19

What are the strengths of a systematic sample ? (2)

Answer 19

• avoids researcher bias

- fairly representative

Question 20

What are the weaknesses of a systematic sample ? (3)

Answer 20

• could be unlucky to get an all male sample for example
• very difficult to achieve as it is time consuming, is expensive and requires a lot of effort
• selected participants may refuse to take part

Question 21

What are the strengths of a stratified sample ? (2)

Answer 21

• avoids researcher bias

- representative

Question 22

What are the weaknesses of a stratified sample ? (3)

Answer 22

• identified strata cannot reflect all the ways that people are different
• people may refuse to participate so they may be unable to make up each
• time consuming and requires a lot of effort

Question 23

What are the strengths of an opportunity sample ?

Answer 23

• convenient, saves time and effort

Question 24

What are the weaknesses of an opportunity sample ?

Answer 24

• unrepresentative as participants are drawn from a very specific area
• may be subject to researcher bias as they have complete control and get the selection of participants

Question 25

What are the strength of a volunteer sample ?

Answer 25

• it is easy as it requires minimal time and effort

Question 26

What are the weaknesses of a volunteer sample ?

Answer 26

• volunteer bias, asking for volunteers may attract a certain profile of person so it’ll then be hard to generalise