A03

• What is a random sample?

  A potentially unbiased sample
• Why is a random sample considered potentially unbiased?

  Confounding variables are equally divided
• What enhances the internal validity of a random sample?

  Equal division of confounding variables
• What is a challenge of conducting random sampling?

  It is difficult and time-consuming
• What may be difficult to obtain for random sampling?

  A complete list of the target population
• What does the law of probability suggest about random sampling?

  It produces a more representative sample
• What could happen even with random sampling?

  Sample may still be unrepresentative
• What issue arises if selected participants refuse to take part?

  It resembles a volunteer sample
• What is a systematic sample?

  An objective sampling method
• How does the researcher influence a systematic sample?

  The researcher has no influence once established
• What is a drawback of systematic sampling?

  Participants may refuse to take part
• What does a stratified sample aim to produce?

  A representative sample
• Why is generalization of findings possible with stratified sampling?

  It reflects the population's composition
• What is a limitation of stratified sampling?

  It cannot reflect all differences
• What is an advantage of opportunity sampling?

  It is convenient and less costly
• What is a major disadvantage of opportunity sampling?

  It is unrepresentative of the target population
• How does researcher bias affect opportunity sampling?

  Researchers may avoid certain participants
• What is a key feature of volunteer sampling?

  It requires minimal input from the researcher
• What is a potential issue with volunteer sampling?

  It may attract a specific profile of person
• How might volunteer bias affect research findings?

  It can limit generalizability of findings