Sampling

• What are the 5 types of Sampling Methods?

  Random, Systematic, Stratified, Snowball, Quota
• What is Random Sampling?

  Picking names out of a hat
• Advantages of Random Sampling?

  Quick & easy to do/organise, no bias
• Disadvantages of Random Sampling?


  Might end up with a biased sample- may not be representative- cant generalise results to rest of population
• What is Systematic Sampling?


  System chooses sample
• Advantages of Systematic Sampling?

  Can be quick to organise, avoids bias- researcher has no influence on who is picked
• Disadvantages of Systematic Sampling?

  Not representative- may end up with more of one group than another. Can't generalise results to rest of population
• What is Stratified Sampling?


  Sample divided up into groups- accurately represent people being studied
• Advantages of Stratified Sampling?


  Very representative- generalisations results- apply to rest of population
• Disadvantages of Stratified Sampling?

  Takes a long time to organise
• What is Snowball Sampling?


  Members put in contact with member- builds sample like a snowball
• Advantages of Snowball Sampling?

  Good for researching specialist groups or illegal groups- gain access
• Disadvantages of Snowball Sampling?

  Not representative- may end up with more boys than girls. Can't generalise whole population
• What is Quota Sampling?


  Often used in market research. Respondents are selected because they represent certain groups in total population
• Advantages of Quota Sampling?

  Quick & easy to complete- does not require sampling frame- easy access
• Disadvantages of Quota Sampling?


  Can produce bias selection as selection may be based on 'friendly faces in the crowd' who are willing to answer questions. Not representative- can't generalise to entire population