Sampling types

Question 1

What is self selection / volunteering sampling

Answer 1

Advertise to whole population and use people who respond
Advantages
-It requires little time or effort in finding people
-People who volunteer are less likely not to respond
-It could be the only way to get peoples input
Disadvantages
-Strong biased, people with strong views want to get views out

Question 2

What is Quota Sampling

Answer 2

Where a interviewer is given a quote and told to fill it
Advantages
-Dont need list of whole population
- The interviewer continues until quote is filled, no response = less of a problem
Disadvantages
- It is biased by the interviewer if the selection isn’t random

Question 3

What is Opportunity / Convenience sampling

Answer 3

A sample is chosen out of a selection of population that is convenient for sampler
Advantages
- Data can be gathered rather quickly and easily
Disadvantages
- It isn’t random and can be biased there is no attempt to make the sample representative

Question 4

What is Cluster Sampling

Answer 4

When the whole population can be divided into distinct groups, randomly select a group to survey
Advantages
- It can be more focused
Disadvantages
- Because you only sample certain clusters the results can be less representative of whole population

Question 5

What is Stratified Sampling

Answer 5

If a population is divided into sub-groups, then use the proportion of each out of total population
Advantages
- Sample represents population
Disadvantage
- Time consuming
- People might not respond

Question 6

What is Systematic sampling

Answer 6

Where every nth person or item in the population is selected
Advantages
- It can be used for quality control
- Should give an unbiased response
Disadvantages
- If there is a pattern in the population then the sample could be biased

Question 7

What is Independent

Answer 7

When the probability of one event occurring does doesn’t effect the effect of the other event occurring
P(A and B) = A * B

Question 8

What is mutually exclusive

Answer 8

If one occur then the other event cannot occur

Question 9

What is population

Answer 9

Whole group

Question 10

What is sample

Answer 10

A selected group from the population

Question 11

What is random sample

Answer 11

Every item has a equal chance of being picked
Advantages
- Unbiased, all have a equal chance
Disadvantages
- Need list of whole population
- Need to find each member selected