Читать книгу Practical Statistics for Nursing and Health Care - Jim Fowler - Страница 17

Once the study population has been defined, the next task is to decide which subjects from the population should form the sample. The following list is not exhaustive, but gives a selection of sample designs:

 simple random sampling,

 systematic sampling,

 stratified sampling,

 quota sampling and

 cluster sampling.

The first three designs can be applied to sampling from finite populations, i.e. situations where every member of the study population can be identified. Such is the case in our asthmatic care example (Section 2.4), where a list of all asthmatic patients registered with the GP practice exists. Quota and cluster sampling are used when it is not possible or practicable to enumerate every member of the study population.