probability sampling

Sampling

the process of selecting participants to take part in a study.

Probability sampling

Simple random sampling- each member of the population has an equal chance of being included.

Systematic sampling-involves taking every nth item from the sampling frame.

Stratified random sampling- involved dividing the population into strata ( layers or subgroups.) Random samples from each subgroup are taken in proportion to the numbers in the population.

Non probability sampling

Snowball sampling- when one member of the population is chosen and put in contact with other people.

Quota sampling- finding enough people to match the number of people in the wider population from a particular group.

Purposive sampling- chosen according to a known characteristic.

Opportunistic sample- anyone who is available

Sampling

Relies on the idea that the views of a small group of people will be representative of the views of everyone else.

Sampling frame- list of names from which to choose respondents.