Populations and Sampling

• target population?


  people the psychologist wants to evaluate
• sampling?

  sometimes target population is too big so psychologists take a representative sample of it
• random sampling?

  * everyone has equal chance of being chosen

  (+) tends to be representative AND no bias

  (-) time consuming AND risk of freak sample
• opportunity sampling?

  * ppts selected bc they're convenient

  (+) quick AND cheap to do

  (-) tends to be unrepresentative AND biased AND narrow range of people
• self selected sampling?

  * ppts volunteer themselves

  (+) ethical

  (-) tends to be unrepresentative AND certain types of people tend to volunteer