Types of Experiment

Question 1

Define a Lab Experiment.

Answer 1

Experiment occurring in a controlled environment where the researcher manipulates the IV and measures the effect on the DV, with control over EVs

Question 2

Define a Field Experiment.

Answer 2

Experiment occurring in a natural setting, where researcher manipulates IV and measures effect on DV.

Question 3

Define a Natural Experiment.

Answer 3

Experiment where change in IV isn’t caused by researcher - would’ve happened even in absence of researcher. The researcher measures the effect on the DV.

Question 4

Define a Quasi-Experiment.

Answer 4

Study almost like an experiment but lacks key ingredients. IV isn’t caused by anyone and variables simply exist, e.g. gender or age.

Not an actual experiment.

Question 5

Evaluate Lab Experiments.

Answer 5

Benefits
• High control over EVs - researcher can ensure any effect on DV is caused by change in IV
• Replication more possible vs other experiments bc of high level of control - ensures EVs aren’t introduced when repeating experiments

Disadvantages
• Lack generalisability - lab env doesn’t rep. every day life
• Low external validity - PP can behave unnaturally in an artificial setting
• Demand characteristics - PP know they’re being tested so behave unnaturally
• Low mundane realism - doesn’t represent everyday life

Question 6

Evaluate Field Experiments.

Answer 6

Strength:
•High mundane realism due to natty env.
• High external validity - produce authentic behaviour as PP unaware they’re being studied

Weakness:
• Little control over extraneous variables - relationship between IV and DV unclear
• Almost impossible to replicate
• Ethical issues - PP unware they’re being studied didn’t give consent - invasion of privacy

Question 7

Evaluate Natural Experiments.

Answer 7

Strengths:
• Enable research that otherwise may not be possible due to ethical/practical reasons e.g. institutionalisation
• High external validity - Research based on real life issues and events e.g. effects of natural disaster on stress levels

Weakness:
• Natural events occur rarely, low opportunity for research
• PP not randomly allocated to experimental conditions - unclear whether IV has affected DV

Question 8

Evaluate Quasi-Experiments.

Answer 8

Strengths:
• Same as lab experiments

Weakness:
• Can’t randomly allocate PPs so there may be confounding variables

Question 9

Why is replication important in experiments?

Answer 9

To check that the results of a study are valid and not one-off