Sampling

Question 1

Target population

Answer 1

The group of people the experiment aims to find out about
Such as the average American or Brit etc

Question 2

Sample

Answer 2

A group of people which aims to represent the target population as best as possible
Actual participants used in study

Question 3

Sampling method

Answer 3

Ways of obtaining a sample in an experiment from the target population

Question 4

4 sampling methods

Answer 4

Self selecting
Opportunity
Random
Snowball

Question 5

Self selecting sample

Answer 5

When people volunteer to take part in the study
Done through advertising to participants who will contact researcher if they wish to take part

Question 6

Opportunity sample

Answer 6

Participants produced by selecting who is most readily available to the researcher at the time (convenience)

Question 7

Random sample

Answer 7

A technique where each member of the target population has an equal chance of being selected
Like drawing names from a hat

Question 8

Snowball sample

Answer 8

Where participants will be asked to contact their friends and family to take part in research who will then ask their friends and family etc

Question 9

Self selecting sample strengths

Answer 9

Participants consented to join the study so gained informed consent (ethics)
So less likely to withdraw and also more likely to cooperate

Question 10

Self selecting sample weaknesses

Answer 10

May lack in terms of diversity: perhaps not enough people of certain backgrounds/jobs/ ethnicities didn’t volunteer or won’t include shy people
Cost of advertising
Might not get enough Ps in general

Question 11

Opportunity sample strengths

Answer 11

Convenient and doesn’t include extra work of getting participants

Question 12

Opportunity sample weaknesses

Answer 12

Biased/lacks in diversity based on where sample was randomly taken
Less ethical since participants will feel less prepared and perhaps obliged to continue

Question 13

Random sample strengths

Answer 13

No bias from researcher since all had an equal chance of being selected
More representative therefore of target population since everyone had an equal chance of being selected

Question 14

Random sample weaknesses

Answer 14

Participants may be less willing to participate if they were suddenly dropped into it
So more likely to withdraw causing bias in the sample
Difficult to get the whole total target population to have everyone be of equal chance to get picked

Question 15

Snowball sample strengths

Answer 15

Less work for researchers since there will be less participants to acquire at first
Ps will convince more people to join if they ask family/friends themselves than if the researcher asked

Question 16

Snowball sample weaknesses

Answer 16

Might be a bias in who participants will ask such as avoiding asking people who they think won’t score well so lacking in diversity w
Participants will share characteristics of who they ask so lacks in diversity

Question 17

Small sample strengths and weaknesses

Answer 17

Easy to manage on a practical level for data and the experiment but not enough measurements will be taken to confirm a consistent effect across whole target population so less reliable

Question 18

Large sample strengths and weaknesses

Answer 18

Hard to manage on a practical level but provides sufficient measurements to suggest a consistent effect
So more reliable

Question 19

What does a sample need to be?

Answer 19

Representative of the target population so findings can be generalised to the whole population
Cost + time effective

Question 20

Biased sample

Answer 20

A sample that doesn’t represent the target population or people in general

Question 21

Gender bias

Answer 21

If a sample has majority male or female, it will have a gender bias
Androcentric = bias by mainly studying males

Question 22

Age bias

Answer 22

If certain age ranges are omitted, the sample is not representative of all people eg only using students

Question 23

Culture bias

Answer 23

By representing only 1 culture or country, the generalisability to other countries is low

Question 24

When is a sample biased?

Answer 24

The sample is not diverse in terms of age/gender/ethnicity/culture/background
The sample was acquired by self select so may be biased in favour of including helpful people
Allowing people to withdraw may bias the sample is only include those who performed well