sampling/ data

Question 1

What is continuous data ?

Answer 1

any value in a range

Question 2

What is discrete data ?

Answer 2

data that can only take certain values in a range

Question 3

What is the population ?

Answer 3

complete set of items that share a common property

Question 4

What is census ?

Answer 4

Where every member of the population provides data

Question 5

What is a sample ?

Answer 5

a subset of the population which is used to collect data from

Question 6

What is a random sample ?

Answer 6

Where members of the population have an equal chance of being picked

Question 7

What is a biased sample ?

Answer 7

Where the sample is not random

Question 8

What should the sample size of a population roughly be (using n as the population)

Answer 8

√n (square root population size)

Question 9

Give an advantage of using a census

Answer 9

accurate results as representative of the entire population

Question 10

Give a disadvantage of using a census

Answer 10

time consuming as large amounts of data to organise and analyse

Question 11

Give an advantage of using a sample

Answer 11

quick to organise and analyse the data

Question 12

Give a disadvantage of using a sample

Answer 12

small sample sizes can lead to inaccurate results as not representative of the entire population

Question 13

What are the 5 different sampling techniques ?

Answer 13

1) random
2) stratified
3) cluster
4) quota
5) systematic

Question 14

What is the method of how to use random sampling ? (2)

Answer 14

1) Uniquely number every member of a population
2) Randomly select n different numbers using a random number generator

Question 15

Give an advantage of using random sampling

Answer 15

useful if the population is small

Question 16

Give a disadvantage of using random sampling

Answer 16

if the population is very big, it can be time consuming to number/ list every member of the population

Question 17

What is stratified sampling ?

Answer 17

Where the population is divided into groups based on demographics and then a random sample is conducted within each group.

Question 18

What is the method on how to use stratified sampling ? (2)

Answer 18

1) calculate the number of members to be randomly sampled from each group
2) take a random sample from each group

Question 19

How would you calculate the number of members to be randomly sampled within each group when using stratified sampling ?

Answer 19

The proportion of a group that is sampled is equal to the proportion of the population that belong to that group

Question 20

What is an advantage of using stratified sampling ?

Answer 20

useful when very different groups of people within a population to make sure the data collected will still be representative of the population structure

Question 21

What is a disadvantage of using stratified sampling ?

Answer 21

groups may not be easy to select as the groups may overlap

Question 22

What is cluster sampling ?

Answer 22

This is when the population already falls into groups / clusters, a random number of these clusters are then selected to be sampled.

Question 23

What is the method on how to conduct cluster sampling ?

Answer 23

1) identify the clusters within the population
2) randomly select a number of clusters to use
3) use all the members in these selected clusters

Question 24

Give an advantage of using cluster sampling

Answer 24

easy to complete as well as inexpensive

Question 25

Give a disadvantage of using cluster sampling

Answer 25

the clusters selected may not be representative of the entire population

Question 26

What is quota sampling ?

Answer 26

When the population is split into groups and members of the population are selected until each quota is filled.

Question 27

How would you conduct quota sampling ? (2)

Answer 27

1) calculate how many people you need from each group
2) select members from each group until the quota in each group is filled

Question 28

What is an advantage of using quota sampling ?

Answer 28

useful when a sampling frame is not available

Question 29

What is a disadvantage of using quota sampling ?

Answer 29

members sampled in each group to fill the quota do not have to be randomly sampled, thereby potentially creating a biased sample.

Question 30

What is systematic sampling ?

Answer 30

Where the population is put into an ordered list and every nth member of this list is selected.

Question 31

What is an advantage of using systematic sampling ?

Answer 31

can be performed quickly by a computer

Question 32

What is a disadvantage of using systematic sampling ?

Answer 32

could miss out members of the population with differing characteristics so not be representative.

Question 33

What is an advantage of using primary data ?

Answer 33

tailored to your specific needs

Question 34

What is a disadvantage of using primary data ?

Answer 34

costly and time consuming

Question 35

What is an advantage of using secondary data ?

Answer 35

cheap and not time consuming

Question 36

What is a disadvantage of using secondary data ? (2)

Answer 36

may be outdated and not be specific to your needs.

Question 37

What is an advantage of using continuous quantitative data ?

Answer 37

easy to interpret numerical continuous data.

Question 38

What is a disadvantage of using continuous quantitative data ?

Answer 38

potentially large amounts of different data which can be hard to organise and analyse.

Question 39

What is an advantage of using discrete quantitative data ?

Answer 39

easy to organise and analyse

Question 40

What is a disadvantage of using discrete quantitative data ?

Answer 40

averages may be decimals

Question 41

What is an advantage of using qualitative data ?

Answer 41

can express the feelings of the group and so be much more constructive and helpful

Question 42

What is a disadvantage of using qualitative data ?

Answer 42

time consuming for large sample sizes and often difficult to interpret.