Laboratory Experiments: Conducted in artificial environments where every variable except the IV is kept constant to prevent 'extraneous variables' from skewing results.
Field Experiments: Carried out in natural social settings (like schools or workplaces) where participants are often unaware they are being studied, reducing artificial behavior.
The Comparative Method: A 'thought experiment' that compares two similar groups or societies using existing secondary data to identify why they differ in specific outcomes.
Random Assignment: A technique used to ensure that participants in the experimental and control groups are similar, reducing the impact of individual differences.
Understanding the differences between experimental types is essential for selecting the appropriate methodology for a specific research question.
| Feature | Laboratory Experiment | Field Experiment | Comparative Method |
|---|---|---|---|
| Setting | Artificial/Controlled | Natural/Real-world | Data-based/Historical |
| Control | Very High | Low | None (Post-hoc) |
| Validity | Low (Artificial) | High (Natural) | High (Real data) |
| Reliability | High (Standardized) | Medium | Low (Hard to repeat) |
| Ethics | Informed Consent | Deception common | Few issues |
Identify the Variable: In any exam scenario, clearly label the and first to understand the researcher's logic.
The Hawthorne Effect: Always check if participants know they are being watched; if they do, their behavior may change, which invalidates the results.
Evaluate the Trade-off: When asked to evaluate a method, use the 'Reliability vs. Validity' framework—lab experiments gain reliability but lose validity, while field experiments do the opposite.
Ethical Check: For field experiments, always mention the lack of informed consent and the potential for deception as a major limitation.
Correlation vs. Causation: Students often assume that because two variables change together, one caused the other; experiments are specifically designed to prove the latter, not just the former.
Control vs. Constant: A 'control group' is a group of people, whereas a 'controlled variable' is a condition (like temperature or time) kept the same for everyone.
Generalizability: Just because a lab experiment works on 20 students doesn't mean it applies to the whole of society; this is a common critique of small-scale experimental research.
