sampling methods

• What does opportunity sampling involve?

  Using whoever is available and willing
• What must participants in opportunity sampling meet?

  Criteria of the target population
• Why is opportunity sampling less time-consuming?

  It uses available participants at the time
• How does opportunity sampling affect a researcher's budget?

  It is less likely to exceed the budget
• When is opportunity sampling particularly useful?

  When no sampling frame exists
• What is a major weakness of opportunity sampling?

  It may produce a biased sample
• What risk is associated with researcher bias in opportunity sampling?

  Researchers may selectively ask certain people
• What does volunteer sampling involve?

  Participants selecting themselves to take part
• How do participants respond in volunteer sampling?

  By responding to an advert for participants
• What is a strength of volunteer sampling?

  Access to a variety of potential participants
• What is a weakness of volunteer sampling?

  Volunteers may share similar characteristics
• What is random sampling?

  Every member has an equal chance to participate
• How is random sampling conducted?

  By giving each member an equal chance
• What methods can be used for random sampling?

  Random number generator or drawing names
• What must participants in random sampling provide?

  Consent to be studied
• What is a strength of random sampling?

  It produces an unbiased sample
• How does randomisation affect researcher bias?

  It removes unconscious influence during selection
• What is a weakness of random sampling?

  It requires obtaining names of the population
• What is systematic sampling?

  Selecting every nth person from a list
• How does a researcher select participants in systematic sampling?

  By calculating a random nth number
• What is a strength of systematic sampling?

  It provides an unbiased selection process
• What is a weakness of systematic sampling?

  It may still have researcher bias
• What does stratified sampling involve?

  Identifying subgroups within the target population
• How does a researcher calculate proportions in stratified sampling?

  By calculating percentages of subgroups
• What is a strength of stratified sampling?

  It produces a highly representative sample
• How does randomisation affect stratified sampling?

  It removes researcher bias during selection
• What is a weakness of stratified sampling?

  It is very time-consuming to conduct
• Why is stratified sampling more expensive than other methods?

  It requires identifying and contacting subgroups