Experiments in Psychology

Experiments in Psychology

Lab Experiments

• Features:
• Researcher controls as many variables as possible
• Done in a controlled environment (such as a lab) using a standardised procedure
• Participants randomly allocated to groups
• Variable details:
• Manipulation of IV
• Measure DV
• Ethical Issues:
• Consent
• Withdrawal
• Deception
• Use of animals
• Examples in psychology:
• Milgram
• Burger
• Strengths:
• All variables can be controlled, reducing their impact on the results
• Standardised procedures make replication easy - more reliable
• Good for establishing cause and effect relationships between IV and DV
• Access to technical equipment
• Weaknesses:
• Low ecological validity due to artificial environment
• Subject to experimenter bias
• Demand characteristics may affect the outcome of the experiment

Field Experiments

• Features:
• Performed in the natural environment of those being studied
• Variable details:
• IV is manipulated
• DV is measured
• Ethical issues:
• Consent/Withdrawal
• Confidentiality
• Use of animals
• Deception
• Examples in psychology:
• Sherif
• Strengths:
• High ecological validity due to natural setting
• Reduced demand characteristics
• Weaknesses:
• Less control over variables
• Less reliable as conditions are unlikely to be the same again
• Sample bias - participants aren't randomly allocated to groups
• Time consuming and expensive
• Limited access to technical equipment

Natural Experiment

• Features:
• Researcher makes use of naturally occurring differences in the IV
• Variable details:
• IV occurs naturally
• DV is measured
• Ethical issues:
• Consent/Withdrawal
• Protection of participants
• Confidentiality
• Strengths:
• High ecological validity due to natural environment
• Reduced demand characteristics
• Lack of experimenter intervention
• Weaknesses:
• Less control over variables
• Less reliable - situation is unlikely to be the same again
• Sample bias - participants aren't randomly allocated
• Time consuming and expensive
• Difficult to use technological equipment
• Likelihood of desired behaviour being displayed is very rare