sampling

Question 1

what is random sampling

Answer 1

when every person in a target population has an equal chance of being selected in the sample
achieved by picking out names out of a hat or a computer

Question 2

2 advantages of random sampling

Answer 2

. quick and easy to carry out
. ensures people all have an equal chance of being chosen

Question 3

2 disadvantages of random sampling

Answer 3

. requires an accurate, up to date and complete sampling frame
. can be unrepresentative e.g sample could be made up of all females

Question 4

what is quota sampling

Answer 4

before the research is carried out the researcher decides how many respondents of a particular type are needed
e.g need 10 boys and 10 girls
then they go out and look for right number and once quota filled they stop gathering results

Question 5

2 advantages of quota sampling

Answer 5

. allows researcher to control the variables without having a sampling frame - knows how many people with particular characteristics to question
. quick and cheap method. e.g if someone refuses to answer questions they can ask someone else with same characteristics

Question 6

2 disadvantages of quota sampling

Answer 6

. not random as each person in the population doesnt have same chance of being asked
. researcher may have to ask few personal questions to see if respondent matches criteria which may put them off

Question 7

what is stratified sampling

Answer 7

splitting sample into groups and selecting randomly from these groups
groups the researcher chooses from must be same proportion as in the target population studied for representativeness

Question 8

2 advantages of stratified sampling

Answer 8

. effective as it allows researcher to control variables that are also important to the research
. can also increase precision and therefore likely to improve representativeness

Question 9

2 disadvantages of stratified sampling

Answer 9

. complex and time consuming to identify strata and to sample various sub groups of the target population
. often not practical as sampling frame may not contain information required to split population into groups eg at a school wanting to look at ethnicity but schools may not list pupils by ethnic group

Question 10

what is snowball sampling

Answer 10

non representative technique involving personal contacts to build sample group - friend telling friend

Question 11

2 advantages of snowball sampling

Answer 11

. no sampling frame is needed
. can allow access to sensitive and secretive groups like drug users

Question 12

2 disadvantages of snowball sampling

Answer 12

. not representative as people who are included are a part of network of contacts
. may run out of participants making it difficult to generalise

Question 13

what is convenience/opportunity sampling

Answer 13

non representative technique involving selecting those who are conveniently available to the researcher

Question 14

2 advantages of opportunity sampling

Answer 14

. quick, cheap and easy
. no sampling frame needed

Question 15

2 disadvantages of opportunity sampling

Answer 15

. sample not representative
. sample is biased as choice of person relies on researcher

Question 16

what is systematic sampling

Answer 16

every nth person in the sampling frame is selected

Question 17

2 advantages of systematic sampling

Answer 17

. should provide unbiased sample
. relatively easy to carry

Question 18

2 disadvantages of systematic sampling

Answer 18

. not truly random

Question 19

what is sample frame

Answer 19

list of people from which samples are drawn from