sampling

Question 1

population

Answer 1

any set of things we want to study

Question 2

census

Answer 2

when we collect data about every member of a population

Question 3

sampling frame

Answer 3

list of every member of a population

Question 4

pros of a census

Answer 4

data for every member of the population

Question 5

cons of a census

Answer 5

-may not have a sampling frame
-time consuming and expensive
-might be destructive

Question 6

opportunity sampling

Answer 6

taking the opportunity to collect data for a sample as and when it arises, without any more planning

Question 7

opportunity sampling pros

Answer 7

-quick cheap easy
-doesnt require a sampling frame

Question 8

opportunity sampling cons

Answer 8

unlikely to give a representative sample

Question 9

quota sampling

Answer 9

involves making sure that proportions of groups in a sample are the same as they are in the population

Question 10

quota sampling pros

Answer 10

-quick, cheap and easy
-easy to compare data for groups within a sample
-more representative sample than opportunity sampling

Question 11

quota sampling cons

Answer 11

-may still not give a representative sample
-need the right data for the population to create the quotas

Question 12

simple random sampling

Answer 12

involves taking a list of the entire population and selecting numbers totally at random from that list

Question 13

simple random sampling pros

Answer 13

by giving every member of the population an equal chance of being selected, we are likely to get a representative sample

Question 14

simple random sampling cons

Answer 14

-you need a sampling frame
-you need a way of choosing randomly from your sampling frame
-doesnt guarantee a really representative sample

Question 15

systematic sampling

Answer 15

involves taking a list of the entire population, choosing a random starting point, and then sampling every nth person from that point on, until the sample is large enough

Question 16

systematic sampling pros

Answer 16

you don’t need to randomly select every member of your sample
-more likely to get a representative sample than with opportunity sampling or quota sampling

Question 17

systematic sampling cons

Answer 17

-you need a sampling frame
-doesnt guarantee a really representative sample
-there are certain samples you could never get

Question 18

stratified sampling

Answer 18

dividing a population into groups, ensuring that our sample has the same proportion of members from the different groups, and then randomly selecting numbers from each group

Question 19

stratified sampling pros

Answer 19

very likely to give a really representative sample

Question 20

stratified sampling cons

Answer 20

-can be tricky to decide which groups in your population are the most important
-incredibly time-consuming to do well

Question 21

random sampling methods

Answer 21

stratified, simple random, systematic. Each member of the population an equal chance of being selected