2. Types of Experiments

Question 1

Types of experiments

Answer 1

• Laboratory experiments
• Field experiments
• Natural experiments
• Quasi experiments

Question 2

What is a Laboratory experiment

Answer 2

A controlled, artificial environment where the independent variable is manipulated.

Question 3

PROS of Laboratory experiments

Answer 3

1. Controlled environment - so effects of extraneous variables are minimised
2. Strictly controlled so easily replicated to check findings
3. Able to draw casual relationships - it’s possible to establish whether one variable actually causes change in another.

Question 4

CONS of Laboratory experiments

Answer 4

1. Artificial environment so low mundane realism as it might not measure real-life behaviour
2. Demand characteristics - participants may respond according to what they think is being investigated, which can bias the results.
3. Ethical issues - deception is often used, making informed consent difficult

Question 5

What is a Field experiment

Answer 5

• Conducted outside the laboratory.
• Behaviour is measured in a natural environment but basic scientific procedures are still followed as far as possible.
• The IV is manipulated. The effect on the dependent variable is measured

Question 6

PROS of Field experiments

Answer 6

1. Less artificial than laboratory experiments, so higher mundane realism
2. Natural environment, so avoids participant effects (if they are not aware of the study), therefore should produce behaviour which is more natural & valid (less demand characteristics)

Question 7

CONS of Field experiments

Answer 7

1. Less control - confounding variables may be more likely in a natural environment + extraneous variables are less easy to control, therefore less able to show cause & effect
2. Ethical issues - P’s who didnt agree to take part might experience distress & often cant be debriefed. (can’t give informed consent)

Question 8

What is a Natural experiment

Answer 8

• Where researcher looks at how an independent variable, which is NOT manipulated, affects a dependent variable.
• IV is not manipulated as it’s an even which occurs naturally.

Question 9

PROS of Natural experiments

Answer 9

1. Few ethical issues - it’s possible to study variables that it would be unethical to manipulate. In this case, IV is NOT manipulated.
2. Demand characteristics - participants may not know theyre in a study, so their behaviour is likely to be more natural.
3. Ecological validity - less artificial than laboratory experiments.

Question 10

CONS of Natural experiments

Answer 10

1. Casual relationships - bc you dont manipulate the IV, & bc other variables could be having an effect, it’s hard to establish casual relationships.
2. Ethics - deception is often used, making informed consent difficult. Also, confidentiality may be compromised if the community is identifiable.
3. Many extraneous variables which are a threat to ‘cause-effect’ conclusions

Question 11

What is a Quasi experiment

Answer 11

• Researcher isnt able to use random allocation to put participants in different conditions.
• This is bc the IV is a naturally existing characteristic between ppl & has NOT been changed by anyone or anything.

Question 12

PROS of Quasi experiments

Answer 12

1. Control - often carried out under controlled conditions
2. Ecological validity - the research is often less artificial than laboratory studies, so you’re more likely to be able to generalise results to real life.

Question 13

CONS of Quasi experiments

Answer 13

1. Cannot randomly allocate participants to each condition, & so confounding variables (eg. what area P lives in) may affect results.
2. It can be hard to establish cause & effect bc the IV isnt being directly manipulated.

Question 14

Examples of naturally existing characteristics between ppl (Quasi experiment)

Answer 14

Biological sex, eye colour, gender, IQ, existence of a mental disorder, etc