research methods

• What is a population in an experiment?

  The group of individuals being investigated
• What is a sample in research?

  A smaller group representative of the population
• What does experimental design refer to?

  How participants are allocated to conditions of the IV
• What are the characteristics of independent groups design?

  • Each participant takes part in one condition of the IV
  • Fewer demand characteristics
  • No order effects
  • Requires more participants
  • Participant variables could act as CVs
  • Controlled through random allocation
• What is a key advantage of independent groups design?

  Fewer demand characteristics
• What is a disadvantage of independent groups design?

  More participants required than repeated measures
• How are participant variables controlled in independent groups design?

  Through random allocation of participants
• What are the characteristics of repeated measures design?

  • Each participant takes part in all conditions of the IV
  • Requires fewer participants
  • No participant variables
  • Higher chance of demand characteristics
  • Order effects may occur
  • Controlled through counterbalancing
• What is a key advantage of repeated measures design?

  Fewer participants required
• What is a disadvantage of repeated measures design?

  Higher chance of demand characteristics
• How are order effects controlled in repeated measures design?

  Through counterbalancing using the ABBA procedure
• What are the characteristics of matched pairs design?

  • Participants are matched into pairs based on characteristics
  • Each pair is randomly allocated to one condition of the IV
  • Fewer participant variables and demand characteristics
  • No order effects
  • Time-consuming and expensive to match
  • Each pair is randomly assigned to conditions
• What is a key advantage of matched pairs design?

  Fewer participant variables
• What is a disadvantage of matched pairs design?

  Time-consuming and expensive to match participants
• How is investigator bias controlled in matched pairs design?

  By randomly assigning each pair to conditions
• What are the characteristics of random sampling?

  • All members of a population have an equal chance of selection
  • Often uses the lottery method
  • No researcher bias
  • Biased sample possible due to non-participation
  • Difficult, expensive, and time-consuming
• What is a key advantage of random sampling?

  No researcher bias
• What is a disadvantage of random sampling?

  Biased sample due to non-participation
• What are the characteristics of systematic sampling?

  • First person chosen randomly
  • Every nth person selected thereafter
  • Same strengths and limitations as random sampling
• What are the characteristics of stratified sampling?

  • Subgroups (strata) identified within a population
  • Represented in the sample as they appear in the population
  • More representative than other methods
  • Time-consuming
  • Not all subgroups may be represented
• What is a key advantage of stratified sampling?

  More representative than other methods
• What is a disadvantage of stratified sampling?

  Time consuming to implement
• What are the characteristics of volunteer sampling?

  • Participants self-select to take part
  • Ethical as participants choose to participate
  • Volunteer bias may occur
• What is a key advantage of volunteer sampling?

  Ethical as participants choose to participate
• What is a disadvantage of volunteer sampling?

  Volunteer bias may occur
• What are the characteristics of opportunity sampling?

  • Selecting anyone available at the time
  • Quick and economical
  • Volunteer bias may occur
  • Researcher bias possible if only approachable people chosen
• What is a key advantage of opportunity sampling?

  Quick and economical
• What is a disadvantage of opportunity sampling?

  Volunteer bias may occur