Experimental design

• RIM

  Repeated measures

  Independent groups

  Matched pairs
• Repeated measures- dealing with situational variables

  All participants experience both conditions

  A repeated measures design guarantees that we are comparing like with like

  There may be order effects

  It is more likely that the participants will work out the aims of the study
• Order effects

  Repeating two tasks may create boredom or fatigue that may cause deterioration in performance in the second task

  To deal with this researchers use counterbalancing:

  Counterbalancing is where half the participants do task A then B and half the participants do task B then A
• Independent group design- dealing with participant variables

  
  

  Two separate groups experience two different conditions of the experiment

  The performance of these two groups is compared

  The participants who occupy each condition are not the same - participant variables may affect the outcome

  To deal with this researchers use random allocation
• Matched pairs- dealing with participant variables

  Participants are matched based on characteristics such as age or ability and are randomly allocated to a different condition

  It is hard to match people exactly as you would need a large target population

  This is an attempt to control participant variables