L5 Sampling methods

• What is the term used for the population that we are interested in sampling?


  Target population
• What does it mean for a sample to be representative?


  It means how alike the sample is to the rest of society
• What are the four different sampling methods used to recruit participants?

  1. Random
  2. Opportunity
  3. Systematic
  4. Stratified
• How can we remember the four sampling methods?


  By using the acronym ROSS
• What is random sampling?


  It is when every member of a population has an equal chance of being selected
• How is random sampling typically conducted?


  By putting names in a hat and pulling them out
• What is a strength of random sampling?


  It eliminates selector bias, making it fairer
• What is a weakness of random sampling?


  It takes more time to carry out than other methods
• What is opportunity sampling?


  It involves using anyone who is available and willing to participate
• What is a strength of opportunity sampling?


  It takes less time to carry out than other methods
• What is a weakness of opportunity sampling?


  It can lead to selector bias, making it less fair
• What is systematic sampling?


  It involves selecting participants based on a dice being rolled and every nth term is chosen
• How is systematic sampling typically conducted?


  By rolling a dice and selecting every 'nth' participant
• What is a strength of systematic sampling?


  Its unbiased since the selection is random
• What is a weakness of systematic sampling?


  It may still result in a biased sample by bad luck
• What is stratified sampling?


  It involves selecting participants to exactly represent the population
• What is a strength of stratified sampling?


  It provides a truly representative sample
• What is a weakness of stratified sampling?


  It takes more time and can be expensive to do
• What is a potential issue with opportunity sampling regarding participant selection?


  There is a possibility of selector bias
• What are the strengths and weaknesses of random sampling?


  Strengths:

  • No selector bias
  • Everyone has an equal chance of being selected

  
  

  Weaknesses:

  • Takes more time than other methods
• What are the strengths and weaknesses of opportunity sampling?


  Strengths:

  • Takes less time to carry out
  • Very easy to do

  
  

  Weaknesses:

  • Selector bias present
  • Not everyone has an equal chance of being selected
• What are the strengths and weaknesses of systematic sampling?


  Strengths:

  • No bias from participant selection
  • Fairly straightforward process

  
  

  Weaknesses:

  • May still result in biased samples by chance
  • Takes more time than opportunity sampling
• What are the strengths and weaknesses of stratified sampling?


  Strengths:

  • Truly representative sample
  • Reflects the population accurately

  
  

  Weaknesses:

  • Time-consuming and expensive
  • Difficult to achieve a genuinely stratified sample