sampling

• Define 'Target population'

  Who you intend on generalising the findings from the research to and from where the sample is drawn from.
• Define 'random sampling'

  All people in target population have a equal chance of being selected for the sample
• Advantages and disadvantages of random sampling

  + Avoids researcher bias as the researcher is not selecting the p's

  
  

  - Can produce can unrepresentative sample. For example, may pull out more males than females.

  - Time-consuming and difficult to get a full list of target population.
• How to conduct random sampling?

  Place all names in a hat and randomly pull out names from the hat.
• Define 'Systematic sampling'

  All people in the sample frame are in a database, every Nth person is selected. E.g - every 10th person.
• Advantages and disadvantages of systematic sampling

  +Avoids researcher bias as the researcher can not choose the p's they want in their sample

  
  

  - Can produce an unrepresentative sample e.g - more males than females.

  - If the target population is large, getting a full list would be difficult
• Define 'opportunity sample'

  Researcher asks available members to take part in the research, easy and often used.
• Advantages and disadvantages of opportunity sample

  + Fastest way to get a sample for research and reduced costs.

  
  

  - Potential researcher bias as the researcher decides who to ask and who not to ask to be in their study.
• Define 'Volunteer sampling'

  Participants offer to take part in research, NOT asked by researcher. They likely saw an advert online/newspaper.
• Advantages and disadvantages of volunteer sampling

  + Minimal effort for the researcher because they simply advertise and p's make contact

  + P's likely to be motivated to complete the study

  
  

  - Volunteer bias as the sample may not be generalisable to the target population as the types of people who volunteer are more likely to have different characteristics to target population.
• Define 'Stratified sampling'

  the process of selecting a sample from a population compromised of various subgroups and then randomly select among each subgroup to form the final sample. (e.g. gender or race)
• Advantages and disadvantages of stratified samplimg

  + More representative to larger target population, results from sample can be generalised.

  + Avoids researcher bias

  
  

  - Time-consuming to establish strata and randomly select from each stratum
• Types of sampling

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