Types of experiments

• Lab Experiments:


  Have high control over confounding and extraneous variables. This can ensure any effect on the DV is likely to be the result of manipulating the IV. Thus, we can be more certain about demonstrating cause and effect.
• Lab experiments:


  Replication is more possible because of the high level of control. This ensures new extraneous variables are not introduced when replicating an experiment. Replication is vital for checking the findings from a study are valid and not just a one-off.
• Lab experiments:


  Lack generalisability due to artificial setting. Low external validity as participants may behave differently/unusually. Higher chance of demand characteristics. Low mundane realism as tasks may not represent everyday experience.
• Field experiments:


  Higher mundane realism than lab experiments because the environment is more natural. Thus field experiments may produce behaviour that is more valid and authentic, especially as participants may be unaware they are being studied.
• Field experiments:


  Less control over confounding and extraneous variables. This means cause and effect between the IV and DV may be more difficult to establish and precise replication is often not possible.
• Field experiments:

  Important ethical issues. If participants are unaware they are being studied they cannot consent to being studied and such research might constitute an invasion of privacy.
• Natural experiments:


  Often have high external validity because they involve the study of real-world issues and problems.
• Natural experiments:


  Provide opportunities for research that may not otherwise be undertaken for practical or ethical reasons.
• Quasi-experiments:


  Often carried out under controlled conditions (can be replicated).
• Quasi-experiments:


  Cannot randomly allocate participants to conditions and therefore there may be confounding variables.
• Natural experiments:


  A naturally occurring event may only happen very rarely, reducing the opportunities for research. Can also limit the scope for generalising findings to other similar situations.
• Natural experiments:


  Participants cannot be randomly allocated to experimental conditions. This means the researcher may be less sure whether the Iv affected the DV.