types of experiments Flashcards
(5 cards)
intro
• All experiments involve a change in the independent variable, where the researcher takes note of the effect of this change on the dependent variable.
• How the IV changes and under which circumstances, varies from one type of experiment to another.
• There are four different types of experiments, all with different strengths and weaknesses.
• Laboratory Experiments
• Field experiments
• Natural Experiments
• Quasi-Experiments
lab experiments
Conducted in a highly controlled environment (not always a laboratory).
Strengths:
• High control of EVs and CVs
• Replication
Weaknesses:
• Lack generalisability / Low External Validity-because of lack of mundane realism-refers to how realistic materials and procedures in experiment actually are in comparison to real life
• Demand Characteristics
field experiment
IV manipulated in natural, everyday setting.
Strengths:
• Higher Mundane Realism
• Higher External Validity
Weaknesses:
• Less control of EVs and CVs - cause and effect harder to establish
• Ethical Issues - consent, privacy
quasi experiment
IV is based on existing difference between people (e.g. age, gender, ethnicity, presence of mental disorder). No one has manipulated this - it simply exists and cannot be changed.
Strengths:
•Often carried out in controlled conditions (high control, replication etc.)
Limitations:
•Confounding variables as cannot use random allocation to conditions
natural experiment
Researcher has no control of IV and cannot change it.
Would have occured even if the experimenter was not studying it. IV is natural, not necessarily the setting.
Strengths:
• Opportunities for research that may not be conducted otherwise - for practical or ethical reasons
• High External Validity-IV is naturally occurring
Limitations:
• Research worthy events may only happen very rarely
• It may not be possible to randomly allocate participants to different conditions (Independent
Groups)
