experimental designs

• what is an INDEPENDENT measures design?

  different participants take part in each condition - vary according to independent variable
• what are the strengths of INDEPENDENT measures design?

  • less likely to experience certain effects
  • easier to establish - effect of changes in groups - due to variable being tested
• what effects are participants less likely to experience in IMD?

  nausea, behavioural, practice
• what are the weaknesses of INDEPENDENT measures design?

  • impossible to control extraneous variable when using different participants in each group - causes inaccurate results
  • larger participant sample required = less efficient
• what is a REPEATED measures design?

  same participants take part in each condition
• what are the strengths of a REPEATED measures design?

  • more accurate results
  • smaller sample required
• why is a smaller sample required in RMD?

  every participant can repeat conditions
• why are there more accurate results in RMD?

  unlikeliness of results being distorted by individual differences
• what are the weaknesses of RMD?

  • possibility of guessing the aim of the tasks - demand characteristics
  • order + fatigue effects - inaccurate behaviours reflection
• what is a MATCHED PAIRS design?

  different participants take part in each condition - matched according to certain characteristics with another in other condition
• what are the strengths of MATCHED PAIRS design?

  • order,practice, fatigue effects - no effect on results
  • unlikely to guess aim of task - condition only seen once
• what are the weaknesses of MATCHED PAIRS design?

  • difficulty and time consuming to match based on characteristics
  • lifestyle complexities
  • variables may alter behaviour differently