Key terms and defintions for data collection in statistics.
Population
The whole set of items that are of interest.
Census
Observes or measures every member of a population.
Sample
A selection of observations taken from the population.
Sampling Unit
An individual unit of a population.
Sampling Frame
A list of sampling units.
Simple Random Sampling
Every sampling unit has an equal chance of being selected.
Systematic Sampling
Each sampling unit are chosen at regular intervals in an ordered list.
Stratified Sampling
Population divided into mutually exclusive strata and simple random sampling carried out in each strata.
Quota Sampling
An interviewer or researcher selects a sample that reflects the characteristics of the whole population.
Opportunity Sampling
Sample taken from people who are available at time of study who meet the criteria.