Types of Experiments

• Laboratory Experiment Weaknesses


  - ecological validity is low as results cannot be applied to real life scenarios

  - participants may display demand characteristics

  - researcher may cause experiment bias
• Laboratory Experiment Strengths


  - high degree of control over extraneous variables (HIGH INTERNAL VALIDITY)

  - cause and effect can be established as all variables are controlled

  - replicable due to being done in a controlled setting with a procedure
• Field Experiment Strengths


  - high ecological validity as the study is placed in a real life setting meaning it can be generalised

  - demand characteristics are reduced as participants are usually unaware that they are being studied

  - cause and effect can be established as the change in theDV is a result of the manipulation of the IV
• Field Experiment Weaknesses


  - lack of internal validity as there may be confounding variables that were unable to be controlled

  - the study is unreliable due to the lack of standardisation

  - the participant may be unaware they are being studied causing ethical issues
• Natural Experiment Strengths


  - high external validity due to being studied on real-life issues and problems as they occur

  - practical and ethical reasons state that this is the best method to use in certain situations
• Natural Experiment Weaknesses


  - lack of internal validity due to there being confounding variables unable to be controlled

  - lack of reliability as a naturally occurring event may only happen very rarely
• Quasi Experiment Strengths


  - practical strength as there is no requirement to set up an artificial environment

  - high external validity because they involve the study of real life issues and problems as the occur
• Quasi Experiment Strengths


  - lack of reliability since it relies on on naturally occurring conditions or specific groups (unable to be replicated)

  - lack of internal validity as the lack of random assignment increases the risk of confounding variables being responsible for the observed effects
• Natural Experiment


  Researcher takes advantage of naturally occurring events to investigate independent variable on dependant variable
• Quasi Experiment


  An experiment in which investigators make use of control and experimental groups that already exist in the world at large. Lacks random assignment