Observer effect
- Actor–observer asymmetry
- Anthropic principle
- Bystander effect
- Demonstration effect
- Hawthorne effect
- Heisenbug
- Laws of Form
- Nocebo
- Observer bias
- Observer effect (information technology)
- Observer effect (physics)
- Observer's paradox
- Observer-expectancy effect
- Personal equation
- Placebo
- Probe effect
- Schrödinger's cat
- Uncertainty principle