Information by Design
Lifestyle Survey Toolkit

Sampling Techniques

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 important that the sampling process is understood and specified before research begins.

Some 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 Lifestyle of Older People in West Sussex used a census.

The Types of Sampling

The process of sampling can be split into two types;