SAMPLING TYPES

• Sampling


  The process of obtaining the participants who will take part in the research
• Sample


  A subset of the population that is relevant to the research topic
• Target population


  The specific population that the researcher wants to investigate
• Generalised population


  A population that is more broad than the target population
• Sampling process


  1. Researcher draws the sample from the target population

  2. Researcher generalises the findings across the target population
• Sampling techniques


  • Stratified
  • Random
  • Volunteer
  • Systematic
  • Opportunity
• Stratified sampling


  • Small-scale reproduction of the target population, dividing and categorising the population by characteristics important to the research
  • The sample is representative of the target population
  • Easy to generalise as the sample is representative
  • Selection is unbiased as it is based on the sub groups in society
• Random sampling


  • Selecting people in a way that everyone has a fair chance of being selected
  • Unbiased selection, meaning it is more likely to be a representative sample
  • Results are able to be generalised to the target population
• Volunteer (self-selected) sampling


  • People volunteer (choose) to take part, selecting themselves as participants
  • Willingness of participants as they are choosing to take part
  • Little effort required to obtain the sample
• Systematic sampling


  • Selecting every nth person from a list to make a sample
  • Unbiased selection, meaning it is more likely to be a representative sample
  • Results can be generalised to the target population
• Opportunity sampling


  • Selecting those who are most convenient, willing and available to take part
  • Quick and easy way to get information
  • Cannot generalise as the sample is likely to be unrepresentative
• Volunteer bias means the results will not be able to be generalised as volunteer participants often have personality traits in common
• Demand characteristics means that volunteer participants may behave how they think the researcher wants them to
• Systematic sampling may not be truly unbiased as the selection process can interact with a hidden periodic trait