A simple random sample is a subset of a statistical population where each member of the population is equally likely to be ...

Stratified random sampling is a method of sampling that divides a population into smaller groups that form the basis of test ...

primary - information that is collected first-hand, eg tallies, measurements and photographs secondary - information that someone else has previously collected and made available, eg on the internet ...

Stratified random sampling - random samples are taken from within certain categories. Stratified systematic sampling - regular samples are taken from within certain categories.

If no other sources are available to measure certain variables of a target population, Statistics Netherlands often uses a random sample, i.e. a sample of units from the population drawn in accordance ...