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.
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 |