Sampling

Sampling

1. Opportunity

   • Whoever happens to go past
   • Lots of unconscious bias
     • Attractive
       • Owe you a favour
   • People in this sample like to help

2. Random

   • Everyone from targer population has same chance of being used
     • Names in a hat is usual method
   • Not everyone chosen will want to take part
     • Have to replace, not as random

3. Volunteer

   • Quick and easy
   • Not typical members of population
     • Helpful
   • Where ad is placed, get certain type of people
     • Students