Sampling

• What is the definition of random sampling?

  A sample where every member has an equal chance
• How can you create a random sample?

  By drawing names from a hat or using random number tables
• What is snowball sampling?

  Sampling that relies on referrals from participants
• How does snowball sampling work?

  Initial participants refer others to join the study
• What is opportunity sampling?

  Sampling from those most easily available
• Give an example of opportunity sampling.

  Using students available in a lesson
• What is stratified sampling?

  Sampling that identifies subgroups in the population
• How is a stratified sample created?

  By selecting randomly from identified subgroups
• If you want 100 participants from a stratified sample, how many A2 males would you select if they make up 15%?

  15 A2 males
• What is systematic sampling?

  Sampling by selecting every nth person
• How can systematic sampling be implemented?

  By using a random number generator for the first selection
• What is self-selected sampling?

  Sampling that relies on volunteers
• How do you recruit participants for a self-selected sample?

  By advertising where the target population can see
• What are the advantages and disadvantages of opportunity sampling?

  Advantages:

  • Quick and convenient
  • Economical compared to other methods

  
  

  Disadvantages:

  • Very unrepresentative samples
  • Biased by researcher selection
• What are the advantages and disadvantages of self-selected sampling?

  Advantages:

  • Convenient and ethical
  • Access to a variety of participants

  
  

  Disadvantages:

  • Unrepresentative due to participant bias
  • Participants may guess study aims
• What are the advantages and disadvantages of random sampling?

  Advantages:

  • Best chance of an unbiased sample
  • Equal chance of selection for all

  
  

  Disadvantages:

  • Time-consuming for large populations
  • Small samples may still be biased
• What are the advantages and disadvantages of systematic sampling?

  Advantages:

  • Unbiased and objective sampling
  • Less time-consuming than random sampling

  
  

  Disadvantages:

  • Small samples may still be biased
  • Selected individuals may refuse to participate
• What are the advantages and disadvantages of snowball sampling?

  Advantages:

  • Effective for hard-to-reach populations

  
  

  Disadvantages:

  • Representativeness is not guaranteed
  • Initial participants can bias the sample
• What are the advantages and disadvantages of stratified sampling?

  Advantages:

  • Highly representative of the target population

  
  

  Disadvantages:

  • Time-consuming to gather
  • Rarely used in Psychology