Sampling General population Target population Sample Sampling l

Sampling General population Target population Sample

Sampling l Researchers aim to get a sample that is representative of the target population l l Every type of person in the TP should be proportionally represented in the sample NB: it is not necessary for the sample to be representative of the GP unless the researcher intends to generalise

Sampling l Opportunity sampling l l Use whoever is immediately available e. g. go out and accost passers-by Volunteer sampling l Use whoever puts themselves forward e. g. advertise in the paper

Sampling l Quota sampling l l Design a sample to reflect the TP and then recruit to order Random sampling l l Every member of the target population has an equal chance of being selected E. g. selected by computer from the electoral roll

How difficult to obtain Sampling • random • quota • opportunity • volunteer How likely to be representative