experimental designs

• lab experiment:

  • IV manipulated, conducted in a highly controlled environment
• strengths of lab experiments:

  • high control of EVs and CVs
  • replication
• weaknesses of lab experiments:

  • lack of generalisability/ low external validity
  • demand characteristics
  • mundane realism
• field experiment:

  • IV manipulated in natural, everyday setting
• strengths of field experiments:

  • higher mundane realism
  • higher external validity
• weaknesses of field experiments:

  • less control of EVs and CVs
  • ethical issues: consent + privacy
• natural experiment:

  • researcher has no control of IV and cannot change it - would have changed even if it wasn't researched
• strengths of natural experiments:

  • opportunities for research that wouldnt be conducted otherwise
  • high external validity
• weaknesses of field experiments:

  • may happen rarely
  • not possible to randomly allocate to conditions
• quasi experiment:

  • IV based on existing research between people e.g gender, age - not manipulated but in artifical setting
• strengths of quasi experiments:

  • often carried out in controlled conditions
• weaknesses of quasi experiments:

  • confounding variables - can't use random allocation of conditions