Types of experiments

Question 1

Experimental method

Answer 1

Involves the manipulation of an independant variable to measure the effect on the dependant variable. Experiments may be laboratory, field, natural or quasi.

Question 2

Laboratory experiment

Answer 2

An experiment that takes place in a controlled environment within which the researcher manipulates the IV and records the effect on the DV, whilst maintaining strict control of extraneous variables.

Question 3

Field experiment

Answer 3

An experiment that takes place in a natural setting within which the researcher manipulates the IV and records the effect on the DV.

Question 4

Natural experiment

Answer 4

An experiment where the change in the IV is not brought about by the researcher but would have happened even if the researcher has not been there. The researcher records the effect on a DV they have decided on.

Question 5

Quasi experiment

Answer 5

A study that is almost an experiment but lacks key ingredients. The IV has not been determined by anyone (the researcher or any other person) - the ‘variables’ simply exist, such as being old or young. The IV is a naturally occurring difference between participants

Question 6

Two strengths of lab experiments

Answer 6

• The extraneous variables are controlled so there is a clearer cause and effect.
• Replication is more possible in lab experiments than other experiments as there is a high level of control.

Question 7

Two weaknesses of lab experiments

Answer 7

• It is may lack generalisability as it is artificial so not like everyday life.
• It is time consuming and hard to organise.

Question 8

Two strengths of field experiments

Answer 8

• There is a higher mundane realism than lab experiments as the environment is more natural. This may produce behaviour that is more valid and authentic.
• Participants may be unaware they are being studied leading to high external validity

Question 9

Two weakness of field experiments

Answer 9

• The natural environment leads to little control of confounding and extraneous variables so the cause and effect between DV and IV could be hard to establish.
• Participants may be unaware they are being studied meaning they cannot consent to being studied which could be an invasion of privacy.

Question 10

Two strengths of quasi-experiments

Answer 10

• Often carried out under controlled conditions therefore can be replicated more easily.
• These controlled conditions mean extraneous variables are controlled so there is a clearer cause and effect.

Question 11

Two weaknesses of quasi-experiments

Answer 11

• They cannot randomly allocate participants to conditions therefore there may be confounding variables.
• The IV is not deliberately changed by the researcher therefore it cannot be claimed that the IV has caused any observed change.

Question 12

Two strengths of natural experiments

Answer 12

• Provides opportunities for research that may not be undertaken otherwise due to ethical or practical reasons.
• There is a high external validity because they involve the study of real world issues and problems as they happen.

Question 13

A weakness of natural experiments

Answer 13

The IV is not deliberately changed by the researcher therefore it cannot be claimed that the IV has caused any observed change.