Sampling

Question 1

What is a population?

Answer 1

Large group of people that a researcher is interested in studying

Question 2

What is a sample?

Answer 2

The participants taking part in the experiment, drawn from a target population which it is presumed to be representative of.

Question 3

What should a sample be?

Answer 3

Generalisable

Question 4

What do we mean by generalisable sample?

Answer 4

Sample should be drawn to representative of the population

Question 5

What are the 5 types of sampling techniques?

Answer 5

• Opportunity sample
• Volunteer sample
• Random sample
• Systematic sample
• Stratified sample

Question 6

What is opportunity sample?

Answer 6

-People who are most available

Question 7

How to carry out an opportunity sample?

Answer 7

Ask people nearby

Question 8

Strengths of opportunity sample:

Answer 8

Convenient and quick

Question 9

Limitations of opportunity sample:

Answer 9

Biased = unrepresentative of target population

Question 10

What is volunteer sample?

Answer 10

Participants select themselves

Question 11

How to carry out a volunteer sample?

Answer 11

Advertisement to get the participants to volunteer

Question 12

Strengths of volunteer sample:

Answer 12

• Willing participants = more likely to engage

- Easy

Question 13

Limitations of volunteer sample:

Answer 13

Biased sample = participants share similar traits (e.g keen, curious)
Cannot generalise to population

Question 14

What is a random sample?

Answer 14

Everyone in the target population has an equal chance of being chosen

Question 15

How to carry out a random sample?

Answer 15

• Lottery method

- Individuals of target population given number, randomly select i.e by random number generator

Question 16

Strengths of a random sample:

Answer 16

Unbiased = researcher has no influence over who is selected

Question 17

Limitations of a random sample:

Answer 17

• Representation of population is not guaranteed
• Time consuming a difficult
• Selected participants may refuse to take part/

Question 18

What is a systematic sample?

Answer 18

Participants selected using a set pattern (sampling frame) - every nth person of the target population is selected

Question 19

How to carry out a systematic sample?

Answer 19

Every nth person is selected from a list of the target population

Question 20

Strengths of systematic sample:

Answer 20

Unbiased = objective

Question 21

Limitations of systematic sample:

Answer 21

Time and effort to make a complete list of population

Question 22

What is stratified sample?

Answer 22

Participants selected by their frequency in the target population

Question 23

How to carry out a stratified sample?

Answer 23

Strata are identified, relative percentage of strata represented in sample

Question 24

Strengths of stratified sample:

Answer 24

-Representative

Question 25

Weakness of stratified sample:

Answer 25

Stratification not perfect = complete representation is not possible as identified strata can't reflect all the ways people are different.