sampling

Question 1

what is random sampling

Answer 1

every member of the target population has an equal chance of being selected

Question 2

how to carry out random sampling

Answer 2

1. compile a list of members of target pop
2. assign each a number
3. use random number generator to select ppts and assign them to conditions

Question 3

strengths of random sampling

Answer 3

• no researcher bias as no influence over ppts selection
• usually fairly representative if big enough sample size

Question 4

weaknesses of random sampling

Answer 4

• difficult and time consuming
• just because someone is selected
  doesn’t mean they have to say yes- so becomes more of a volunteer sample

Question 5

what is systematic sampling

Answer 5

every nth number of the target population is chosen

Question 6

how to carry out systematic sampling

Answer 6

1. compile a list of target population
2. nominate a sampling system

Question 7

strengths of systematic sampling

Answer 7

• no researcher bias as no influence over ppts selection
• usually fairly representative if big enough sample size

Question 8

weaknesses of systematic sampling

Answer 8

• difficult and time consuming
• just because someone is selected
  doesn’t mean they have to say yes- so becomes more of a volunteer sample

Question 9

what is stratified sampling

Answer 9

the composition of the sample reflects the proportions of subgroups within the target population

Question 10

how to carry out stratified sampling

Answer 10

1. researcher first identifies the strata that make up the population
2. proportions are calculated to allow the sample to represent the pop
3. random sampling used to select ppts

Question 11

strengths of stratified sampling

Answer 11

• no researcher bias as no influence over selection
• highly representative as it accurately refelects

Question 12

weaknesses of stratified sampling

Answer 12

• doesn’t reflect all the ways people are different
• usually ends up being a volunteer sample

Question 13

what is opportunity sample

Answer 13

researcher selects anyone who is willing and able at the time of the study

Question 14

how to carry out opportunity sampling

Answer 14

1. ask anyone who is around at the time of the study

Question 15

strengths of opportunity sampling

Answer 15

• minimal effort

Question 16

weaknesses of opportunity sampling

Answer 16

• usually ver unrepresentative as sample drawn from small area
• at risk of researcher bias as they have complete control over selection

Question 17

what is volunteer sampling

Answer 17

self selection method where ppts select themselves

Question 18

how to carry out volunteer sampling

Answer 18

1. put an ad in the locus paper or put up a poster in an appropriate place

Question 19

strengths of volunteer sampling

Answer 19

• minimal effort, time and cost

Question 20

weaknesses of volunteer sampling

Answer 20

• only going to get a certain type of person (extraverted?) meaning the results will lack generalisability