sampling

• Stratified sampling

  Percentage x number of participants
• Opportunity sampling

  • Convenient and less expensive - just select who is available, no need for sorting methods or lists
• Opportunity sampling limitations

  • Researcher bias - selecting people who you think will produce a certain result, complete selection control, avoid whoever they like therefore low internal validity
  • Unrepresentative of target population - drawn from particular area therefore difficult to generalise to target population