Types of Experiment

Question 1

Laboratory experiment

Answer 1

A controlled experiment where extraneous and confounding variables can be regulated

The participants go to the researcher

The IV is manipulated and the effect on the DV is recorded

Question 2

Pros of Lab Experiment

Answer 2

+ Extraneous Variables and Confounding Variables can be controlled - Effect of EV and CV can be minimised - Cause and effect between the IV and DV can be demonstrated ( High internal validity )

+ Can be more easily replicated - findings can be confirmed supporting their validity

Question 3

Cons of Lab experiment

Answer 3

• Demand Characteristics - The controlled lab environment may be rather artificial and participants are aware they are being studied, therefore behaviour may not be natural and cant be generalised to everyday life ( low external validity )

Question 4

Field Experiment

Answer 4

An experiment conducted in a natural environment.

The researcher goes to participants

The IV is manipulated and the effect on the DV is recorded

Question 5

Natural experiment

Answer 5

The experimenter does not manipulate the IV - it does change, but the change is not made by the experimenter - someone or something else causes the IV to vary

DV may be naturally occurring or may be devised by the experimenter and measured in the field or a lab.

Question 6

Quasi - experiment

Answer 6

IV is based on pre-existing difference between people. No one has been manipulated this variable, it simply exists.

DV may be naturally occurring or may be devised by the experimenter and measured in the field or a lab.

Question 7

Pros of field experiment

Answer 7

+ More natural environment - participants more comfortable and behaviour more authentic - Results may be more generalisable to everyday life.

+ Participants are unaware of being studied - They are more likely to behave as they normally do so the findings can be generalised - The study has greater external validity

Question 8

Cons of field experiments

Answer 8

• More difficult to control CV/ EVs - Observed changes in the DV may not be due to the IV but to CVs / EVs instead.
• There are ethical issues - participants in a field experiment may not have given informed consent. - This is an invasion of participants privacy which raises ethical issues

Question 9

Pros of natural experiments

Answer 9

+ May be the only practical / ethical option - It may be unethical to manipulate the IV e.g. studying the effects of institutionalisation on children - a natural experiment may be the only way causal research can be done for such topics.

• Greater external validity - Natural experiments involve real world issues - This means the findings are more relevant to real experiences

Question 10

Cons of natural experiments

Answer 10

• The natural event may only occur rarely - Many natural events are one offs and this reduces the opportunity for research - this may limit the scope for generalising findings to other similar situations.
• Participants are not randomly allocated - Iv is pre existing so experimenter has no control over participants - may result in CVs that aren’t controlled.

Question 11

Pros of quasi-experiment

Answer 11

+ There high control - often carried out in controlled conditions and shares similar strengths as lab - Replication may be possible

+ Comparisons can be made between people - The IV is a difference between people - comparisons between different types of people can be made

Question 12

Cons of quasi-experiment

Answer 12

• Participants are not randomly allocated - Iv is pre-existing - participant variables may have caused the change in the DV acting as a CV
• Causal relationships not demonstrated - the researcher does not manipulate/control the IV - We cannot say for certain that any change in the DV was due to the IV