Experimental design

• What’s Repeated measure designs?

  Participants are in all conditions
• what’s independent measure designs?

  participants are only in one condition
• what’s matched paired designs?

  two groups similar as possible in different conditions

  for example: age, gender, IQ
• strengths and weaknesses of repeated measures design

  STRENGTHS:

  > good control of participant variables as same person is tested twice

  > fewer participants needed.

  WEAKNESSES:

  > order effects are produced

  > participants may guess the research aims and use demand characteristics
• how can you control order effects?

  counterbalancing - have each participant do different order of conditions
• strengths and weaknesses of independent group design

  STRENGTH:

  > avoids order effect

  > avoids guessing aim of study

  WEAKNESSES:

  > no control of participant variables

  > needs more participants than repeated measures design
• how can lack of participant variables be dealt with?

  randomisation
• strengths and weaknesses of matched paired designs

  STRENGTHS:

  > controls for participant variables

  > avoids order affects as its like independent group design

  WEAKNESSES:

  > very time consuming

  > may not contain all variables as only aware of the variables relevant but could find more throughout the experiment