Types of experiments

• Laboratory experiment


  Independent variable is manipulated and dependent variable is measured in a highly controlled/artificial environment
• Field experiment

  IV is manipulated and DV is measured in a natural environment where participants would be regardless of the research taking place
• Natural experiment


  Iv is naturally occuring (so is not manipulated by the researcher) in an everyday environment. The researcher simply records the effect of the IV (which is usually a life event to do with nature on the DV)
• Quasi experiment

  IV is not determined, it is naturally (the variables simply exist) in an everyday environment.
• Ecological validity


  IF a study is high in ecological validity it means the findings can be generalised to real life, as the environment that the experiment was conducted in was reflective of the real world and nit artificial (fake)
• Internal valdity


  Did the Iv produce the change in the DV (or did something else affect the DV, such as an extraneous variable)? If there are strict controls of variables, a study is said to have internal validity.
• Mundane realism


  Refers to whether a task or activity mirrors the real world. Would they do a similar task in their everyday life?
• Reliablity

  Is the experiment easy to replicate? If it was repeated, would we get the same results?
• Demand characteristcis


  When participants know they are taking part in an experiment they may guess what the experiment is about and alter their behaviour to fit in with expectations
• Ethical issues

  Concerning regarding whether the experiment is morally right or wrong
• Laboratory advantages

  - High control over extraneous variables meaning any effect on the DV is likely to be result of manipulation to IV= certain show of high internal validity

  - Replication is possible due to high level of control meaning no new extraneous variables introduced when repeating
• Laboratory disadvantages


  - Lack of generalisability- environment may be artificial meaning cannot always be generalised beyond research setting (low external validity)
• Field advantages

  - Higher mundane realism as environment is more natural

  - Behaviour= more valid + authentic people would not be aware that they are being studied meaning higher external validity
• Field disadvantages

  - Loss of control of extraneous variables= cause and effect between IV and DV may be more difficult to establish

  - Ethical issues- if they are unaware they're being studied is an invasion of privacy
• Natural advantages

  - High external