Sampling Flashcards
unit 1.2
What is simple random sampling ?
every sample having an equal chance of being selected e.g. lottery and generating
What are the advantages of simple random sampling ?
no bias
easy
cheap
What are the disadvantages of simple random sampling ?
not suitable for large populations
What is systematic sampling ?
when required elements are chosen at regular intervals from an ordered list
What are the advantages of systematic sampling ?
simple
quick
suitable for large samples
What are the disadvantages of systematic sampling ?
need a sampling frame
bias
What is stratified sampling ?
it reflects the population in the sample, in proportion
What are the advantages stratified sampling ?
it reflects the population structure
proportional representation
What are the disadvantages of stratified sampling ?
need classifying
simple random within stratums
