Sampling

Question 1

Simple random sampling definition

Answer 1

where the items in the sample are chosen by a
random process such as drawing from a box. Every member of the population has an equal
chance of being selected

Question 2

Opportunity sampling definition

Answer 2

involves choosing individuals for a sample as opportunity arises, such as
interviewing passers-b

Question 3

Systematic sampling definition

Answer 3

involves selecting individuals from a population by a systematic method,
such as selecting every 10th individual on a list of the population

Question 4

Stratified sampling definition

Answer 4

is used when the population can be divided into subgroups (strata) using
criteria such as age or gender, and ensures that all strata are represented in the sample.
Sometimes a requirement that the numbers sampled from each group is proportional
to the sizes of the groups (this is called proportional stratified sampling). Otherwise, weighting is
used.

Question 5

Quota sampling

Answer 5

used when the population can be divided into strata. A certain
number of items from each stratum are required

Question 6

Cluster sampling

Answer 6

used when the population consists of subgroups which are each reasonably
representative of the population (e.g. year 6 classes in several schools). A sample is taken from
just a few of these subgroups