Experiments Flashcards
What is an experiment
An experiment is an investigation looking for a causal relationship in which an independent variable (IV) is manipulated and is expected to be responsible for changes in the dependent variable (DV).
What are the 3 types of experiments
-Field experiment
-Laboratory experiment
-Natural experiment
What is a laboratory experiment
research method in which there is an IV, DV, and strict controls. This looks for a causal relationship and is conducted in a setting which is not the usual environment for the participant with regard to the behaviour they are performing.
What is a field experiment
This is conducted in a setting which is the normal environment for the participant with regard to the behaviour they are performing. The researcher has control over a few variables, but it difficult to control all variables.
Natural experiment
An investigation looking for a causal relationship in which the IV cannot be directly manipulated by the experimenter. Instead, they study the effect of an existing difference or change. This is not a true experiment as the experimenter cannot manipulate the levels of the IV.
Strengths of field experiments
-Realistic setting so high ecological validity
-If participants are unaware that they are in a study, there is very less chance of participants exhibiting demand characteristics, in comparison to lab experiments.
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Weaknesses of field experiments
-Situational variables are difficult to control so it is tough know if the IV is affecting the DV
-Issues in breaking ethics since the participants do not know that they’re taking part in a study
Strengths of lab experiments
-High levels of standardization hence it can be replicated easily to test for reliability
-High levels of control hence researchers can be more confident that the iv is directly affecting the dv
-Allows extraneous variables such as participant variables (individual differences) to be controlled. This helps raise validity
Weaknesses of lab experiments
-Takes place in an artificial environment hence it lacks ecological validity
-since the experiment takes place in artificial settings, there are chances of participants exhibiting demand characteristics and social desirability bias.
-Low mundane realism
Strengths of Natural experiments
High ecological validity because the iv is naturally occurring
Valid representation of a persons behaviour
Weaknesses of natural experiments
-Difficult to know whether the iv caused an effect on the dv
-Difficult to replicate to test for reliability as the event is naturally occurring
