Lesson 5: Sampling

• What is a sample in research?

  A smaller subset of the population
• Why are samples used in research?

  To represent the target population practically
• What is a population in research?

  A large group of individuals studied
• What is sampling bias?

  When a sample under or over represents groups
• How can sampling bias be avoided?

  By using a larger sample size
• What is random sampling?

  Every sampling unit has an equal chance
• What is the method for random sampling?

  Obtain a complete list of target population
• What is the first step in random sampling?

  Assign names an identifying number
• What is the lottery method in random sampling?

  Using a randomiser to select participants
• What is a strength of random sampling?

  Reduces unwanted bias in participant selection
• Why is random sampling more representative than opportunity samples?

  It avoids conscious selection by the researcher
• What is a limitation of random sampling?

  It is difficult and time-consuming to conduct
• What is random allocation?

  How to allocate participants to conditions
• What is opportunity sampling?

  Participants are selected based on availability
• What is a strength of opportunity sampling?

  It is less costly and time-consuming
• What is a limitation of opportunity sampling?

  It often results in an unrepresentative sample
• What is systematic sampling?

  Selecting every nth member from a sampling frame
• What is a strength of systematic sampling?

  It reduces investigator influence over the sample
• What is a limitation of systematic sampling?

  It can still be unrepresentative
• What is stratified sampling?

  Randomly obtaining participants from identified strata
• What is a strength of stratified sampling?

  It ensures proportional representation of subgroups
• What is a limitation of stratified sampling?

  It is difficult and time-consuming to conduct
• What is volunteer sampling?

  Participants self-select to take part in a study
• What is a strength of volunteer sampling?

  It is the least time-consuming method
• What is a limitation of volunteer sampling?

  It attracts people who may bias results