0.5. Experimental methods

Question 1

Laboratory experiment

Answer 1

Conducted in a carefully controlled environment

Question 2

Strengths of a laboratory experiment

Answer 2

• highly controlled environment
• can infer cause and effect relationship
• ethical as ppts know they are taking part
• can be replicated

Question 3

Limitations of a laboratory experiment

Answer 3

• artificial situation
• low ecological validity
• lack of mundane realism
• participant effects (all different)
• demand characteristics

Question 4

Field experiment

Answer 4

Takes place in a natural environment, IV manipulated

Question 5

Strengths of a field experiment

Answer 5

• high ecological validity as conducted in a real life situation
• natural behaviour from ppts

Question 6

Limitations of a field experiment

Answer 6

• less ethical (as ppts are not always aware they’re taking part in an experiment)

Question 7

Natural experiment

Answer 7

Used to investigate a casual relationship in situations where the IV cannot be manipulated by an experimenter

Question 8

Strengths of a natural experiment

Answer 8

• allows research where the IV cannot be manipulated for ethical or practical reasons e.g. studies on privation
• enables psychologists to study real problems (increases mundane realism and validity)

Question 9

Limitations of a natural experiment

Answer 9

• cannot demonstrate casual relationships (IV not directly manipulated)
• a lot of extraneous variables
• can only be used when conditions vary naturally
• ppts may be aware they are being studied (ppt effects, investigator effects, demand characteristics)

Question 10

Quasi experiment

Answer 10

IV not manipulated and based on pre-existing differences in people (age, gender)
The DV is naturally occurring

Question 11

Strengths of a quasi experiment

Answer 11

• allows comparisons between types of people
• high control

Question 12

Limitations of a quasi experiment

Answer 12

• can only be used where conditions vary naturally
• ppts may be aware of being studied, and are not randomly allocated (affects DV)
  The DV may be a fairly artificial task, reducing ecological validity