Stratified Random Sampling

With stratified random sampling, the population is first divided into a number of parts or 'strata' according to some characteristic, chosen to be related to the major variables being studied. For this survey, the variable of interest is the citizen's attitude to the redevelopment scheme, and the stratification factor will be the values of the respondents' homes. This factor was chosen because it seems reasonable to suppose that it will be related to people's attitudes.

The survey will use three strata:

those with houses in the bottom third of values
those with houses in the middle third of values
those with houses in the top third of values

Simple random samples are then selected from each stratum. The same proportion will be selected within each stratum, making the sample a proportionately stratified random sample.

What percentage of each stratum would you like to include in your sample? %
(maximum 10%)

The sampling procedures are:

  1. simple random sampling
  2. clustered random sampling
  3. stratified random sampling
  4. quota sampling
  5. summary and finish