Types of experiment

Question 1

Laboratory experiments

Answer 1

conducted in highly controlled environments

Question 2

Field experiments

Answer 2

The IV is manipulated in a natural, every day setting - the researcher goes to ppts usual environment instead of a lab

Question 3

Natural experiments

Answer 3

• Takes advantage of pre-existing IV - the variable would have changed even if the experimenter wasn’t interested.
• Researcher has no control over the IV and can’t change it - someone or something else causes the IV to vary.
• The IV is natural

Question 4

Quasi experiments

Answer 4

• Has an IV that is based on an existing difference between people.
• No one manipulates the IV it simply exists - unlike a natural experiment the IV can’t be changed.
• The DV may be naturally occurring or devised by the experimenter and measured in the field or a lab

Question 5

Evaluation of lab experiments

Answer 5

• High level of control over confounding and extraneous variables which means the researcher can establish cause and effect.
• Easier to replicate because of high control.
• May lack generalisability and have low external validity.
• May have low mundane realism

Question 6

Field experiments evaluation

Answer 6

• Higher mundane realism than lab experiments because of the natural environment - high ecological validity.
• Ppts are often unaware they are being studied so act more natural.
• Loss of control of cause and effects
• Ethical issues - deception and informed consent

Question 7

Natural experiments evaluation

Answer 7

• provide more opportunity for research that may not otherwise be undertaken for practical and ethical issues.
• Often have high external validity because they involve the study of real life.
• Naturally occurring event may only happen rarely which reduces opportunity for research.
• Ppts may not be randomly allocated to experimental conditions - researcher may be less sure whether the IV is affecting the DV.

Question 8

Quasi experiments evaluation

Answer 8

• Often carried out under controlled conditions - control of extraneous variables - easy to replicate - high internal validity.
• Can’t randomly allocate ppts to conditions and therefore may be confounding variables.
• IV isn’t deliberately changed by the researcher and therefore we can’t claim that the IV has caused observed change