types of experiment

• types of experiment

  laboratory, field, natural and quasi
• lab experiment

  happens in a controlled environment
• strengths of a lab experiment

  high control of extraneous variables, establishing cause and effect relationships, giving it high internal validity

  replication is more possible due to higher level of control
• limitations of a lab experiment

  lacks generalisability as a controlled environment may be artificial so people may behave differently causing low external validity

  demand characteristics are higher

  low mundane realism - doesnt apply to real life
• field experiments

  occurs in a more natural everyday setting where people are unaware that they are in the study
• strengths of a field experiment

  high external validity - natural environment leads to natural behaviour
• limitations of a field experiment

  lack of control over extraneous variables so it is harder to establish cause and effect relationships

  hard to replicate

  ethical issues as people cannot give their consent to participate in the study
• natural experiment

  similar to field but researcher cannot control the iv - for either ethical or practical issues
• strengths of a natural experiment

  provides opportunities for research

  high external validity
• limitations of a natural experiment

  difficult to replicate

  hard to see if the iv has caused the effect on the dv as participants are not randomly assigned to experimental conditions
• quasi experiment


  having an iv based on an existing difference between people e.g. age, gender - iv is not manipulated
• strengths of a quasi experiment

  carried out in controlled conditions so shares same strengths as a lab experiment
• limitations of a quasi experiment

  cannot randomly allocate people to experimental conditions therefore extraneous variables may affect outcome