Sampling is the process of selecting a subgroup of a
population to represent the entire population.
When carrying out any type of survey, it is crucial
that the people interviewed are as representative as
possible of the group that you are studying.
Regardless of the quality of your questionnaire, the
results will only be seen as useful if it is
considered that your respondents are typical of the
whole population. For this reason, it is
that the sampling process is understood and
specified before research begins.
Key Terms in Sampling
A ‘census’ is collecting information from each
member of a group. All the members of a
group are called a ‘population’ – if
only some members of a group are consulted this is
called a ‘sample.’ The list of people
from which a sample is taken is known as the
‘sampling frame’, e.g. electoral register,
postcode address file, GP Register etc.
Lifestyle surveys are usually conducted using
‘sample’ of the population. There are
exceptions – for example, the survey
of Older People in West Sussex used a census.
The Types of Sampling
process of sampling can be split into two types;