Sampling Techniques

Question 1

Random

Answer 1

Each member of target population has equal chance of being selected
Need a list of target population then randomly draw names out of a hat or name generator

Question 2

Random - strength

Answer 2

Unbiased selection- cv/EV are controlled, enhances internal validity

Question 3

Random weakness

Answer 3

Impractical- complete list of population is hard, some participants may may refuse to take party
May not be representative by chance - still end up with sample that’s not representative, may get 20 females in one and 5 in another

Question 4

Opportunity

Answer 4

Involves using participants who are available and willing o take part - asking people in the street

Question 5

Opportunity - strength

Answer 5

Quick and easy - make use of people who are closest - cheaper, popular

Question 6

Opportunity - limitation

Answer 6

Unrepresentative/acts generalisation - unrepresentative of target population - drawn from specific area - findings no generalised

Question 7

Volunteer

Answer 7

Participants select themselves to take part (advert or ask participants to take part)

Question 8

Volunteer - strengths

Answer 8

Easy - select themselves and are willing, less work for researcher, engage more

Question 9

Volunteer - limitation

Answer 9

Volunteer bias - share certain traits (want to be helpful), not generalised
demand characteristics

Question 10

Systematic

Answer 10

Where every nth member of the target population is selected
Need a list of everyone in target population

Question 11

Systematic - strengths

Answer 11

Unbiased selection - first item usually selected at random - objective method
Fairly representative- would be possible but unlikely to get sample o target populaton

Question 12

Systematic - limitation

Answer 12

Only possible if you can identity all member of target population - complete list is required to work, may aswell use random sampling

Question 13

Stratified

Answer 13

Makeup of sample reflects proportions of people i certain subgroups within population
Must identify subgroups then work out proportion to make representative
Then subgroups picked from Radom sampling

Question 14

Stratified - strength

Answer 14

Unbiased/representative - characteristics representative and generalised more than other methods

Question 15

Stratified - limitation

Answer 15

Time consuming - knowledge fo characteristics required, takes time to work out subgroups and them mak sample
Stratified not perfect - have to reflect all ways in which people are different. Complete representation not possible