Sampling

Question 1

What is a random sample

Answer 1

Every member of target pop has equal chance of being selected

Question 2

Strengths of random sample

Answer 2

unbiased
can choose subgroup

Question 3

Weakness of random sample

Answer 3

Time and effort (need list of target pop)
Samples often not random (finding sample, volunteering)

Question 4

What is stratified sample

Answer 4

Participants selected in proportion to sub groups frequency in target pop

Question 5

Strengths of stratified

Answer 5

most Representative (unless people withdraw)
Important subgroups selected (increased control over extraneous variables

Question 6

Weakness of stratified

Answer 6

Biased (researcher decides subgroups)
Lengthy process

Question 7

Volunteer sample what it is

Answer 7

ask people willing to take part (advert)

Question 8

Strengths of volunteer sample

Answer 8

convenient (less likely to withdraw)
purposive sampling (good way to get specialised sample)

Question 9

Weakness of volunteer

Answer 9

biased (volunteers highly motivated)
Demand characteristics

Question 10

Opportunity sample what it is

Answer 10

select people most readily available

Question 11

Strengths of opportunity sample

Answer 11

most convenient (quick)
May be only technique possible (sometimes target pop cant be listed)

Question 12

Weakness of opprtunity sample

Answer 12

Biased (have to be there at the time)
Pps can refuse to take part (volunteer)