Overview
This lecture discusses the importance of having a clear, testable hypothesis in experimental design to ensure scientific studies are robust and reproducible.
The Role of Hypotheses in Science
- Scientific advancements often falter due to poorly designed experiments with unclear hypotheses.
- Good science seeks to answer specific questions through targeted experiments, not by collecting random data.
- A hypothesis provides a clear, understandable explanation for a set of observations.
Hypothesis vs. Pilot Studies
- Collecting large amounts of data without a clear question is called a "hypothesis generating" or pilot study.
- Pilot studies help develop potential hypotheses but should not be treated as definitive research.
- Strong, reproducible experiments are designed around testing a specific hypothesis, not just exploring data for patterns.
Constructing and Testing Hypotheses
- Example: In studying mice activity, possible hypotheses include effects of time of day, food, or number of other mice.
- Experiments are often built around a null hypothesis (no relationship between variables).
- A study should be designed to test the null hypothesis and see if it can be rejected based on evidence.
- Statistical analysis is used to determine if the null hypothesis should be rejected, but scientific conclusions always carry uncertainty.
Best Practices in Experimental Design
- Studies may test more than one hypothesis, but each must have appropriate study design.
- Research must be carefully planned with well-thought-out hypotheses and clear methods to match.
- Researchers must understand their findings’ implications and limitations.
- Good research prepares for both possible outcomes: if the hypothesis is supported or not.
Key Terms & Definitions
- Hypothesis — a clear, testable explanation for a set of observations.
- Null Hypothesis — the default position that there is no relationship between the variables studied.
- Pilot Study — an initial, exploratory study used to generate hypotheses for future, more rigorous testing.
Action Items / Next Steps
- Ensure every experiment you design starts with a clear, testable hypothesis.
- When reading scientific news, distinguish between hypothesis-generating studies and those testing specific hypotheses.