Populations And Samples Flashcards
What is a population?
A whole set of items that are of interest.
What is a census?
Observes or measures every member of a population.
What is a sample?
It’s a selection of observations taken from a subset of the population which is used to find out information about the population as a whole.
Give one advantage and disadvantage of a census.
Advantage: It should give a completely accurate result.
Disadvantage: Time consuming and expensive
Give one advantage and disadvantage of a sample.
Advantage: Less time consuming and expensive than a census.
Disadvantage: The data may not be as accurate.
What is a sampling unit?
Individual units of a sample.
What is a sampling frame?
Sampling units of a population that are individually named or numbered to form a list.
What is simple random sampling?
One where every sample of size n has an equal chance of being selected.
What is systematic sampling?
When the required elements are chosen at regular intervals from an ordered list.
What is stratified sampling?
In stratified sampling, the population is divided into mutually exclusive strata and a random sample is taken from each.
