sampling statergies- Target populations, sample populations and techniques for sampling effectively

Question 1

what must we sample

Answer 1

cost utility

accessibility

Question 2

define target sample

Answer 2

The total finite population we wish to know about from which your sample is drawn

Question 3

define study sample

Answer 3

The units/participants drawn from the target population that constitute our data set

Question 4

what are the 3 main types of sampling

Answer 4

complete
unstartified random
stratified random

Question 5

define complete sampling

Answer 5

the entire study population

Question 6

define unstartified random sampling

Answer 6

Every member of the target population has the same chance of being sampled

Question 7

define stratified random sampling

Answer 7

Randomly sample from the target population within strata (i.e. groups by e.g. sex, age, disease onset, etc)
Every member of the target population within each stratum has the same chance of being sampled

Question 8

what are the pros and cons of complete sampling

Answer 8

Pro: no bias introduced by design
Con: potentially expensive

Question 9

what are the pros and cons of unstratified random sampling

Answer 9

Pro: easy to design and conduct
Con: smaller groups may be under-represented by chance

Question 10

what are the pros and cons of stratified random sampling

Answer 10

Pro: representative of population
Pro: unequal sampling of strata improves power for rare strata
Con: population may not be easily divisible into strata
Con: strata may not be known until after sampling