Stratified Sampling

• Stratified sampling - where the proportions of each group of a population are representated in the sample.
• Advantage of stratified sampling:

  • fairly represents each group
• Disadvantage of stratified sampling:

  • more time consuming / complicated
• Stratified sampling sample frame:

  • obtain a list of elements and break into groups
  • calculate proportions: (group frequency / population size) x sample size
  • repeat for each group, rounding values
  • conduct a simple random sample for each group