experimental methods

• what is a lab experiment

  • highly controlled
  • artificial environment
  • researcher manipulates IV
• what is a field experiment

  • natural environment
  • researcher manipulates IV
• what is a natural experiment

  • IV has been manipulated naturally
  • takes advantage of preexisting IV (trauma)
  • about events experienced
• what is a quasi experiment

  • takes advantage of preexisting IV (autism)
  • about the person
  • includes age and gender
• what is a causal link

  independant variable causes a change in the dependant variable
• advantages of lab experiment

  • more control over confounding and extraneous variables
  • can be replicated
• disadvantages of lab experiment

  • lack generalisability
  • causes demand characteristics- unnatural behavior arises due to pressure of being watched
  • artificial- lacks mundane realism
• advantages of field experiment

  • more mundane realism, due to natural setting
  • high external validity- the participants are unaware they are being studied
• disadvantages of field experiment

  • less control
  • precise replication is not possible
  • ethical concerns- the participants can't consent, therefore its an invasion of privacy
• advantages of a natural experiment

  • high external validity
  • allows opportunities to research topics ethics would prevent from studying (e.g foster children)
• disadvantages of a natural experiment

  • less control
  • not many cases are available
• advantages of a quasi experiment (same as lab)

  • high control over confounding and extraneous variables
  • replication is possible
• disadvantages of quasi experiment

  • hard for randomisation to be set in conditions, so there may be confounding variables (can't be controlled)