sampling

• A target population is the wider group of people you are researching
• A sampling frame is a list of everyone in your target population to generate sample
• A sample is a smaller population to research to then be representative of.
• There are seven main sampling methods which are:

  • Random
  • Stratified
  • Opportunity
  • Snowball
  • Quota
  • Volunteer
  • Systematic
• Random sampling is when each person in the target population has an equal chance of being selected
• Stratified sampling is when the target population is split into sections representing a key group or characteristic needed for the final sample.

  
  

  This is the most representative sample
• Opportunity sampling is where they select research participants in the study, it selects anyone who is willing and available at that time.
• Snowball sampling is when they start with one participant who then recommends to other participants.

  This is the least representative.
• Quota sampling is where they select people based on pre-specified characteristics to match the assumed distribution in the population.
• Volunteer sampling is a non-probability sampling method where they self-select into a study and used when the target population is difficult to access.
• Systematic sampling is where they select the every nth person in regular intervals.

  This is useful when the population is large, diverse or hard to reach however is not representative