Experimental methods

• Key Characteristics of a Laboratory Experiment: there is direct manipulation of the independent, control variables and randomisation to ensure all extraneous influences affect any variables.
• Key Characteristic of Field Experiment: controlled experiments that take place in a natural setting as seeks to measure natural behaviour (participants unaware they in a study). Behaviour is the dependent variable.
• Key characteristics of a Natural Experiment is they occur naturally occurring changes in independent variables are observed (understanding how human behaviour occurs in situations)
• Key Characteristics of a quasi experiment is that they occur naturally as the independent variable is the pre-existing characteristics of the participants. Also cannot be randomly assigned participants.
• Advantages of Lab Experiments is that the independent variable is easily manipulated, it is replicable, cause and effect relationship easily identified.
• Advantages of a field experiments is that they show a clear cause and effect relationship, they have high ecological validity as people aren’t aware they are participating (true behaviour)
• Advantages of Natural experiments is that they have high ecological validity and they are helpful when researchers want to investigate things that would be unethical in lab/field. Helpful to investigate effects of a natural change (trauma victim and compare data)
• Advantages of a Quasi experiment is that they can investigate areas that lab/field experiments can’t as would be unethical. Also how certain charcteristics impact how you are in relation to the hypothesis.
• Disadvantages of a Lab Experiment is that they are not an accurate measure of behaviour as low internal validity- therefore low ecological validity
• Disadvantages of Field Experiments is that there is reduced control of extraneous variables- this might affect the dependent variable as they could become confounding variables. Therefore the cause and effect relationship could be undetermined. Also time consuming
• Disadvantages to natural experiments is that it’s not always clear what the cause and effect relationship is. Leading to low internal validity as extraneous variables could affect the dependent variable as they could turn into confounding variables. Also weak in comparison to lab and field experiment.
• Disadvantage to quasi experiments is that it is not always possible to identify the cause and effect relationship clearly