Experimental designs

• What is a repeated measures design?


  A design that involves the same subjects participating in all conditions of the independent variable.
• What is an independent measures design?

  An experimental design where different participants are used in each condition of the independent variable.
• What is a matched participant design?

  A type of experimental design where participants are matched based on key variables relevant to the study topic.
• Order effects: when the order of IV levels affects the DV (they are boredom, fatigue, and practice)
• Practise effect: when you’re better at something because you’ve done it before
• Boredom effect: when participants get bored during the experiment as they have done it before
• Fatigue effect: participants may be tired when repeating something a second time
• Participant variables are avoided by random allocation
• Strengths of independent measure:

  -decreased demand characteristics

  -affects order effects
• Weaknesses of independent measure:

  -participant variables

  -needs more participants
• Strength or repeated measures:

  -needs less people

  -no participant variables
• Weaknesses of repeated measures:

  -demand characteristics

  -order effects
• Counterbalancing: a technique used to reduce order effects when using repeated measure design. Varies the order in which participants take part in each conditions -AB BA
• Strengths of matched participants:

  -controls participant variables

  -no demand characteristics

  -no order effects
• Weaknesses or matched participant:

  -need more participants

  -time consuming and difficult

  -some participant variables not controlled

  -large group of participants
• Peer review: assessment of scientific work by others who are experts in the same field. It validates new knowledge and ensure integrity. Also prevents 3 types of fraud (falsification, plagiarism, fabrication)
• Purposes of peer review:

  -allocation of research funding

  -publication of research

  -assessing university departments
• Strengths of peer review:

  -done anonymously so reviews can be honest and objective
• Weaknesses of peer review:

  -could be used to settle old scores or bury rival research

  -publication bias, often prefer positive results

  -preference for research that goes with existing theories

  -they may have an opposing viewpoint