Experimental design

• What are the three types of experimental designs?

  Repeated measures, independent groups, matched pairs
• What is an independent groups design?

  • Participants take part in one condition of the IV
  • Different participants are used in each condition
  • Example: One group chews while learning, another does not
• What is a key advantage of independent groups design regarding order effects?

  There are no order effects influencing results
• How does independent groups design reduce demand characteristics?

  Participants are unlikely to guess the aim
• What is a disadvantage of independent groups design related to participant numbers?

  Double the amount of participants is needed
• How can individual differences affect independent groups design?

  They may act as a confounding variable
• What is a repeated measures design?

  • All participants undergo one condition, then the other
  • Conditions may be immediate or at a later date
• What is an advantage of repeated measures design regarding unbalanced groups?

  It eliminates unbalanced groups by self-comparison
• How does repeated measures design affect the number of participants needed?

  Less participants are needed compared to independent groups
• What is a disadvantage of repeated measures design related to order effects?

  Results may be influenced by practice or boredom
• How do demand characteristics affect repeated measures design?

  Participants are more likely to guess the study's aim
• What is a matched pairs design?

  • Participants are tested for key variables before the study
  • Similar participants are paired up
  • One from each pair experiences a different condition
• What is an advantage of matched pairs design regarding unbalanced groups?

  It attempts to eliminate unbalanced groups
• How does matched pairs design reduce demand characteristics?

  Participants only take part in one condition
• What is a disadvantage of matched pairs design regarding participant numbers?

  At least double the amount of participants is needed
• Why can matched pairs design be time-consuming and difficult to achieve?

  Participants can never be matched exactly
• What is a potential cost issue with matched pairs design?

  Matching may be time-consuming and expensive