Overview
This lecture explains the scientific method, a step-by-step process used in biology and other sciences to solve problems and test hypotheses logically and systematically.
Steps of the Scientific Method
- The scientific method consists of six steps: observation, question, hypothesis, prediction, test, and iteration.
- The process begins with making an observation that sparks curiosity.
- Next, a question is formulated about the observation.
- A hypothesis, or testable explanation, is proposed.
- A prediction is made based on the hypothesis.
- The prediction is tested through experiment or further observation.
- Results guide the next iteration: refining the hypothesis or forming a new one.
Example: Toaster Problem
- Observation: The toaster does not toast bread.
- Question: Why didn't the toaster work?
- Hypothesis: Maybe the electrical outlet is broken.
- Prediction: If the outlet is broken, plugging the toaster into another outlet will work.
- Test: Move toaster to another outlet and try again.
- Results: If bread toasts, hypothesis is supported; if not, new hypotheses are needed.
Nature of Hypotheses and Evidence
- A valid hypothesis must be testable and falsifiable; it cannot be about untestable opinions.
- A hypothesis is not the same as a theory; theories are broader and well-supported by evidence.
- Supporting evidence cannot conclusively prove a hypothesis but can make it likely correct.
- Contradictory evidence can disprove a hypothesis in principle, but practical errors may complicate this.
- Scientific knowledge builds as evidence accumulates and alternative explanations are ruled out.
Iterative Process
- The scientific method is cyclic, using feedback from results to refine questions and hypotheses.
- Supported hypotheses may be tested further or specified more narrowly.
- Unsupported hypotheses lead to new questions and hypotheses.
Key Terms & Definitions
- Hypothesis — a testable and falsifiable possible answer to a scientific question.
- Theory — a broad explanation supported by extensive evidence from multiple sources.
- Prediction — an expected outcome if a hypothesis is correct.
- Iteration — repeating the scientific method process, using results to inform next steps.
Action Items / Next Steps
- Practice applying the scientific method to real-life or experimental situations.
- Review additional examples or exercises on hypothesis testing and experimental design.