Overview
This lecture introduces the scientific method and demonstrates its application through examples, including a historical case study on the disease beriberi.
The Scientific Method
- The scientific method tests questions that arise from observations.
- Steps include observation, question formation, background research, hypothesis, experiment, data analysis, and conclusion.
- If results do not support the hypothesis, scientists review experiments and refine or form new hypotheses.
- Communication of results is important, typically through publications or discussions.
What is Science?
- Science aims to explain the natural world by investigating patterns and processes.
- Defined as experimental, hypothesis-driven investigation to uncover patterns and their governing processes.
- Cause and effect relationships are central to scientific explanations.
Scientific Jargon & Variables
- Independent variable (cause) and dependent variable (effect) have various synonyms, e.g., X and Y, driver and responding variable.
- In sentences, the cause is the subject, the effect is the object, and the verb links them.
Formulating Scientific Questions
- Scientific questions investigate relationships between causes (independent variables) and effects (dependent variables).
- Using clear language enables effective communication of these relationships.
Example of Scientific Method: Broken Toaster
- Observation: Toaster does not toast bread.
- Question: Why doesn't the toaster work?
- Hypothesis: The electrical outlet is faulty.
- Prediction: If the outlet is faulty, the coffeemaker won’t work there either.
- Experiment: Plug in coffeemaker to outlet.
- Analysis: If coffeemaker works, hypothesis is unsupported.
Case Study: Beriberi and Thiamine Deficiency
- In 1887, beriberi (nerve disease) showed symptoms like weakness and heart failure.
- Initial hypothesis: disease caused by bacteria; both injected and non-injected chickens became ill.
- Revised hypothesis: disease linked to diet, specifically thiamine deficiency in polished rice.
- Conclusion: Chickens on polished rice (without thiamine) developed beriberi, supporting the nutrient deficiency cause.
Key Terms & Definitions
- Scientific Method — systematic process for investigating questions, including observation, hypothesis, experiment, and analysis.
- Hypothesis — an educated guess or prediction to answer a specific question.
- Independent Variable — factor that is changed or controlled in an experiment (cause).
- Dependent Variable — factor being tested or measured (effect).
- Thiamine — a vitamin essential for health; its deficiency causes beriberi.
Action Items / Next Steps
- Complete the online lab exercises on the scientific method with the provided scenarios.
- Review the beriberi case study for understanding of hypothesis testing and variable identification.