research methods: types of experiment

Question 1

What are the four types of experiments?

Answer 1

• laboratory experiment
• field experiment
• natural experiment
• quasi experiment

Question 2

What is a laboratory experiment?

Answer 2

A place in which research can be conducted under highly controlled conditions. Uses standardised procedures

Question 3

Who manipulates the IV in lab experiments?

Answer 3

The experimenter who uses standardised procedures

Question 4

Where is the DV measured in lab experiments?

Answer 4

In a lab so may be artificial

Question 5

What are the strengths of a laboratory experiment?

Answer 5

• lab experiments have high control over confounding and extraneous variables
• therefore, the researchers can be confident in establishing a cause and effect relationship between the changes in the IV and the observed difference in the DV
• High internal validity means that the observed change in the DV is due to a change in the IV
• Lab studies are easily replicated due to the standardised procedures

Question 6

What are the limitations of lab studies?

Answer 6

• Lab studies lack ecological validity, a type of external validity
• This means findings from a lab study cannot be applied to a range of real-world situations
• May lack generalisability as tasks as the environment and tasks conducted may be rather artificial and not reflect real life situations -> low mundane realism
• Participants are aware they are in a study so may alter their behaviour due to demand characteristics

Question 7

What is a field experiment?

Answer 7

Conducting the experiment in naturalistic settings

Question 8

Who manipulates the independent variable in field experiments?

Answer 8

The experimenter

Question 9

Where is the DV measured in field experiments?

Answer 9

In a field in an attempt to avoid the artificial nature of lab studies

Question 10

What are the strengths of field experiments?

Answer 10

• Has higher mundane realism than lab experiments because the environment is more natural
• Thus field experiments produce behaviour that is more valid and authentic
• This is because pps may be unaware they are being studied so will not show demand characteristics

Question 11

What are the limitations of a field experiment?

Answer 11

• Field studies lack control over possible extraneous variables that could be influencing the measurement of the dependent variable
• It is also difficult to randomly assign participants to separate conditions, resulting in a change in DV that may be due to participant variables, reducing internal validity

Question 12

What are natural experiments?

Answer 12

When the researcher takes advantage of the pre-existing IV so the variable will naturally change, even if the researcher wasn’t there

Question 13

Who manipulates the IV in natural experiments?

Answer 13

By someone/something in the environment, not the experimenter

Question 14

Where is the DV measured in natural experiments?

Answer 14

In a natural environment

Question 15

What are the strengths of a natural experiment?

Answer 15

• provide opportunities for research that may not otherwise be undertaken for practical or ethical reasons
• High in external validity as natural experiments are an example of real behaviour occurring in the real world free of demand characteristics

Question 16

What are the limitations of a natural experiment?

Answer 16

• A naturally occurring event may only happen very rarely, reducing the opportunities for research
• this may also limit the scope for generalising findings to other similar situations
• also can’t be replicated for reliability
• participants may not be randomly allocated to experimental conditions so the researcher may be less sure whether the IV affected the DV

Question 17

What are quasi experiments?

Answer 17

When participants cannot be randomly assigned between levels of IV as it is based on an existing difference between people

Question 18

Who manipulates the IV in quasi experiments?

Answer 18

Based on an existing difference that cannot be randomly allocated to conditions e.g. gender or age

Question 19

What are the strengths of a quasi experiment?

Answer 19

• The only way to experimentally study factors that are pre-existing characteristics of participants
• often carried out under controlled conditions so share some strengths of a lab experiment (e.g. replication and high internal validity)

Question 20

What are the limitations of a quasi experiment?

Answer 20

• The IV is not deliberately changed by the researcher and therefore we cannot claim that the IV has caused any observed change and could be the effect of confounding variables
• Cannot randomly allocate participants to conditions and therefore there may be confounding variables