Experimental Methods

• Lab Experimental Method


  P knows they are in a study

  High Control, the researcher manipulates variables they are testing

  Usually control and experimental group

  Cofounding variables held constant
• Advantages of Lab Study

  There is high control over variables (more extraneous variables can be controlled), this means the IV is causing the change in the DV

  Replicability - because of the high control in the procedures, this means the study should be easily repeated to see if other researchers achieve the same results, if they find similar results the study is reliable.
• Disadvantages of Lab study

  Lacks ecological validity. It is artificial and the Ps are unlikely to encounter the scenarios in everyday life, this means we cannot generalise to real life.

  Demand Characteristics - Ps know they are being studied and attempt to guess the aim, so they will try to act in a way they believe the researcher would want or sabotage the study, meaning the results are not valid.
• Field Experimental Method


  Increased realism by carrying it out in a naturalistic environment

  Iv is manipulated

  Ps do not know they are in an experiment
• Advantages of a Field Experimental Method

  High ecological validity - less artificial so validity is higher and we are able to generalise to other real life scenarios

  Reduces Demand Characteristics - The Ps are unaware they are taking part in a study so they shouldn't work at the aim and change their behaviour so we can trust the results are valid.
• Disadvantages of a Field Experimental Method

  Loss of control - cofounding variables could easily influence the results as the researcher as no control of the environment

  Ethical issues - lack of informed consent and protection of Ps - they may feel embarrassed from being studied without knowing.
• Natural Experiment Study


  The researcher does not manipulate the IV, instead they take advantage of something naturally occurring

  There is no control by researcher
• Advantages of Natural Experiment Study


  Reduces demand characteristics

  Lack of direct intervention and manipulation - it is possible through that just the presence of a researcher has an effect of Ps behaviour
• Disadvantages of Natural Experiment Study


  Loss of control

  Ethical issues
• Quasi Experimental Study


  This is almost a lab experiment, but where the IV cannot be determined by anyone, because it already exists (predetermined), such as gender.
• Advantages of a Quasi Experimental Study

  High Control
• Disadvantages of Quasi Experimental Study

  Lacks ecological validity

  May have a bias sample as Ps can't be randomly allocated into groups.