Sampling 2

Question 1

Formula for number sampled in stratum

Answer 1

Number samples in stratum = over all sample size x number in stratum/number in population

Question 2

Simple random sampling adv

Answer 2

Adv
Free of bias
Easy and cheap to implement for small populations and samples
Each sampling unit has an equal chance of selection

Question 3

Simple random sampling dis adv

Answer 3

Dis adv
Not suitable for large population and sample size
Sampling frame is needed

Question 4

Systematic sampling adv

Answer 4

Systematic sampling adv
Simple and quick to use
Suitable for large samples and large populations

Question 5

Systematic sampling dis adv

Answer 5

Dis adv
Sampling frame is needed
It can introduce bias if the sampling frame is not random

Question 6

Stratified sampling adv

Answer 6

Stratified sampling is accurately reflects population structure
Guarantees proportional representation of groups within population

Question 7

Stratified sampling dis adv

Answer 7

Dis adv
Population must be clearly classfied into distinct strata
Selection from k each stratum suffers from same dis adv as random sampling

Question 8

Describe Quota sampling

Answer 8

Quota sampling is when an interviewer selects a sample that reflects characteristics of whole population

Question 9

How is quota sampling carried out

Answer 9

Population is divided into groups according to given characteristic. Size of each group determines proportion of sample that should have characteristic.
Interviewer would meet people, assess them and allocate them to the appropriate quota. If person refuses to be interviewed then they are ignored.

Question 10

Opportunity/convenience sampling

Answer 10

Consists of taking sample from people available at time of study and they fit criteria you’re looking for.

Question 11

Quota sampling adv

Answer 11

Quota sampling adv
Allows small sample to still be representative of population
No sampling frame
Quick,easy, inexpensive
Allows for easy comparison between different groups.

Question 12

Quota sampling dis adv

Answer 12

Non random sampling can lead to bias
Population must be divided
Increasing scope of study increases groups, time and expense.

Question 13

Convenience/opportunity sampling adv

Answer 13

Adv
Easy to carry out
Inexpensive

Question 14

Convenience/opportunity sampling dis adv

Answer 14

Dis adv
Unlikely to provide a representative sample
Highly dependent on individual researcher