Dealing with Extraneous Variables

• Participant Variables: EV's related to individual characteristics of each ppt that may impact how they respond

  Examples: background differences, mood, intelligence

  Deal through: Repeated measures design, Matched pairs design
• Order Effect: Refers to the differences in ppt's responses that result from the order in which materials presented

  Examples: ppt becoming better at task, getting bored or work aim out

  Deal through: Independant groups design, Matched pairs design, ABBA design
• Situational Variables: Factors in the environment that can unintentionally affect the DV in a study

  Examples: noise, temperature, odours

  Deal through: Standard procedures
• Researcher effects: These occur when a researcher unintentionally influence the outcome of research

  
  

  Examples: non verbal communication, physical characteristics, bias interpretation of data

  
  

  Deal through: Double blind design