POPULATIONS, SAMPLES, SAMPLING METHODS

Question 1

Target population

Answer 1

Group of people psychologists want to be able to generalise their findings to.
Psychologists need to take sample of people who are reflective of target population wanting to be studied.

Question 2

Sampling

Answer 2

Selecting ps from population, should be representative of target population, the more representative, the more confident researcher can be that results can be generalised to target population.

Question 3

Problems with generalisability

Answer 3

Only studying people from one area.
May be bias in age ( too many old or young )
More men than women ( gender bias ) May only be reflective of one ethnic origin.

Question 4

Gender bias

Answer 4

Sample made of people from one gender, not representative of all.

Question 5

Androcentric

Answer 5

Biased towards men, all male sample.

Question 6

Estrocentric

Answer 6

Biased towards women, all female sample.

Question 7

Cultural bias

Answer 7

Sample too focused on one culture, not representative of all cultures.

Question 8

Ethnocentric

Answer 8

Sample biased to one culture/ ethnicity.

Question 9

Population validity

Answer 9

Can we generalise results from our sample to target population?

Question 10

4 Sampling methods

Answer 10

Opportunity
Self-selected (volunteer)
Random
Snowball

Question 11

Opportunity sampling

Answer 11

Easiest, most common, cheapest.
Using people readily available to you, willing to partcipate.

Question 12

Strengths of opportunity

Answer 12

-easiest, quickest
-most economical, cheap
-easy access to psychologist
-only sampling method for some research methods (covert= undercover experiment/observation)

Question 13

Weaknesses of opportunity

Answer 13

-likely to produce biased sample
-only certain types of people selected from limited geographical areas
-not representative

Question 14

Self-selected/ volunteer sampling

Answer 14

People who want to take part volunteer themselves.
Psychologist places advert such as a poster or a flyer, those interested reply and psychologist filters responses to collect sample reflecting their target population.
Then contact ps to take part.

Question 15

Strengths of volunteer

Answer 15

-target/request ps who may have features required for investigation
-convenient and ethical, informed consent
-people more likely to be committed, no sample attrition.

Question 16

Weaknesses of volunteer

Answer 16

-unrepresentative-leads to biased sample
-no responses to advert unless they have a strong interest or view.
-demand characteristics likely (act accordingly to aim)

Question 17

Random sampling

Answer 17

Every member of target population has equal chance of being selected.
Names needed of all members of target population, all potential ps are entered into a draw, names are randomly selected until desired number of ps is chosen.
Random name/ number generator can be used.
Ps then contacted to take part.

Question 18

Strengths of random

Answer 18

-least biased method, all members of target population equal chance of selection
-representative sample of target population

Question 19

Weaknesses of random

Answer 19

-difficult and time consuming to do
-harder to do with larger target populations
-Representative sample not always guarenteed.

Question 19

Snowball sampling

Answer 19

Used if population not easy to contact, achieved by asking a ps to suggest someone else who may be willing to take part/ appropriate for study.
Useful in hard to obtain populations; drug users, truants etc…

Question 20

Strengths of snowball

Answer 20

-possible to access members of groups where no lists/ identifiable clusters even exist e.g criminals.
-good to gather samples of groups hard to access

Question 21

Weaknesses of snowball

Answer 21

-can be slow process, time consuming
-no way of knowing if sample is representative as ps are usually friends of friends.