Sampling

Sampling

1. Sampling means getting opinions from a number of people, chosen from a specific group, in order to find out about the whole group

2. Sample Design

   • Sample designs can vary from simple to complex, depending on the type of information required
   • Sample design affects the size of the sample and the way in which analysis is carried out
   • The sample design may make use of the characteristics of the overall market population, but it does not have to be proportionally representative
   • Many sample designs are built around the concept of random selection

3. Types of Sampling

   • Cluster sampling
     • A random sample of clusters is taken, then all units within the cluster are examined
     • Quick and easy, good for face to face surveys
     • Expensive if the clusters are large, greater risk of sampling erro
   • Judgment sampling
     • A deliberate choice of a sample
     • Good for providing illustrative case studies
     • Samples often small
   • Convenience sampling
     • Uses those who are willing to volunteer and easiest to involve in the study
     • Large amounts of information can be gathered quickly
     • Prone to volunteer bias