Types of experiments Flashcards
True laboratory experiment
a) Determine whether a cause-and-effet relationship exists between two variables
b) IV manipulated by the researcher (Control)
c) Set in a laboratory
d) Can infer causation
Advantage of true laboratory experiment
Avoid extraneous variables
a) Variables that might influence the behaviour of a participant
Disadvantage of true laboratory experiment
Low ecological validity
a) Not reflects what happens in real life
Independent variable
Manipulated variable that causes a change in other
Dependent variable
Measured variable after the manipulation of the independent variable
Control variables
Other variables must be exactly the same
Key features of tru laboratory experiments
a) Operationalization
b) Standardization
c) Random allocation
Operationalization
It is clear what is being measured
Standardization
Procedures and results can be replicated by another researcher
Random allocation
Participants have the same chance of being assigned to the experimental or control condition.
Experimental hypothesis
Predicts the relationship between the IV and the DV
Null hypothesis
States IV will have no effect on the DV
Goal of testing experiments
a) Reject the null hypothesis
b) Accept the null hypothesis
True field experiment
a) IV manipulated by the researcher
b) Set in real life context
c) Inference of causation with extraneous variables
Disadvantages of true field experiments
a) Cannot control for extraneous variables
b) Cannot be easily replicated
Ethical considerations of true field experiments
a) Not getting informed consent
b) Debriefing
Quasi experiment
a) No manipulation of the IV
b) Set in laboratory
c) No inference of causation
Distribution of participants into groups in quasi-experiments
No random allocation. Participants are group based on a trait or behavior
Natural experiment (Subset of quasi-experiment)
a) IV is environmental in nature and outside of the control of the researcher
b) Set in real-life context
c) DV measured before and after the variable was introduced
d) No inference of causation
Disadvantages of quasi experiments
a) Do not show direct causation
b) Influence of confounding or extraneous variables
What to evaluate in an experiment
a) Extraneous variables
b) Participant variability
c) Demand characteristics
d) Artificiality
e) Researcher bias
Extraneous variables
Undesirable variables that influence the relationship between the IV and DV
Demand characteristics
Participants form an interpretation of the experiment’s purpose and subconsciously change their behavior to fit that interpretation
Researcher bias
When the experimenter sees what he or she is looking for.
