Sampling

• Sampling: The process of selecting a subset of a target population as representation of the population to be studied. The results from the study will then be generalised to the wider population.
• random sampling is a method of selecting a sample from a population by selecting people at random. every person has an equal chance of being selected.
• advantage of random sampling

  Free from researcher bias
• disadvantages of random sampling

  Time-consuming
• stratified sampling: a sampling technique that involves dividing a population into groups based on characteristics and then randomly selecting a sample from each group
• advantage of stratified sampling

  Greater representation of the population.
• disadvantage of stratified sampling

  Expensive and time-consuming
• opportunity sampling is when a researcher selects participants that are willing and available at the time
• advantage of opportunity sampling

  Time-efficient and convenient
• disadvantage of opportunity sampling

  Prone to researcher bias
• systematic sampling is when a researcher selects every nth person from a target population for research.
• Advantage of systematic sampling

  Avoids researcher bias
• Disadvantage of systematic sampling

  Time consuming
• volunteer sampling is when ppts put themselves forward in response to an advertisement to be part of a study (self-selection)
• advantage of volunteer sampling

  Easy and minimal effort
• Disadvantage of volunteer sampling

  Volunteer bias - demand characteristics