sampling

• Strength of random sampling

  • avoids bias
  • researcher cannot choose px they want to form the sample
  • avoids possibility of researcher picking px they feel are likely to give preferred result
• Strength of stratified sampling

  • sample is representative of larger population
  • results should be generalisable to target population
  • researcher bias is avoided as px are randomly chosen from within each stratum
• examples of stratas/subgroups

  • ethnicity
  • gender
  • education level