Experimental Methods (types)

• Define a laboratory experiment and its one strength and weakness

  A procedure staged in an artificial environment

  
  

  (+) = highly controlled = no extraneous variables = easy to replicate due to standardised procedures

  
  

  (-) = demand characteristics = ppts know they are being studied
• Define a natural experiment and its strength and weakness

  A study that examines a naturally occurring variable in a real- life situation.

  
  

  (+) = IV occurs naturally = high ecological validity

  
  

  (-) = can’t control extraneous variables = findings lack internal validity
• Define a quasi experiment and its two strength and two weakness

  A procedure in a naural/lab setting where the IV is differences between individuals (race, age etc)

  
  

  (+) If in lab = highly controlled = no extraneous variables = easy to replicate due to standardised procedures

  
  

  (+) If in natural = IV occurs naturally = high ecological validity

  
  

  (-) If in lab = more likely to have artificial setting/task = demand characteristics more likely (not authentic behaviour = difficult to generalise)

  
  

  (-) If in natural = difficult to control extraneous variables = findings lack internal validity
• Define a field experiment and its two weaknesses

  A procedure staged in a naturalistic environment (IV is still being manipulated)

  
  

  (+) Natural occuring environment = the setting has high mundane realism = the findings have a higher ecological validity

  
  

  (+) Less demand characteristics = ppts don't know they are in an experiment

  
  

  (-) = Difficult to control extraneous variables (other variables that effect the results of the study) in the field = reducing internal validity of the experiment

  
  

  (-) = Consent as ppts don't know they are in an experiment