Overview
This lecture explains the steps of the scientific method, using the example of making popping boba, and highlights how to conduct and analyze experiments logically.
Steps of the Scientific Method
- Science often begins with an observation that raises a question.
- The scientific method is a systematic process to answer questions with experiments.
- Steps include: formulating a testable question, researching background information, constructing a hypothesis, designing and conducting an experiment, analyzing data, and communicating results.
Formulating a Question
- Start with a question that is specific and testable, often beginning with who, what, when, where, why, or how.
- Good scientific questions can be investigated through experiments, not just answered by reading.
Background Research
- Gather information from books, internet, or experts to understand your topic.
- Learn about necessary materials, procedures, and factors affecting the experiment.
Constructing a Hypothesis
- A hypothesis is an educated guess based on background research, phrased as a testable prediction.
- Example: "If I use acidic liquids, then popping boba will be less spherical."
Experimental Design & Variables
- Identify independent variable (what you change), dependent variable (what you measure), and controlled variables (what you keep the same).
- For popping boba: independent = acidity; dependent = boba shape; controlled = temperature, ingredient amounts.
- Write step-by-step procedures and repeat experiments for reliability.
Data Collection & Troubleshooting
- Record all steps, measurements, and observations in a lab notebook.
- If problems occur, adjust the procedure and repeat the experiment.
- Document everything with notes, drawings, or photos.
Analyzing Results
- Analyze data by calculating averages, making graphs, and checking data quality.
- Graphs should place the independent variable on the x-axis and dependent on the y-axis, with units labeled.
- Use results to determine if the hypothesis is supported; negative results are also valuable.
Communicating Findings
- Share results in a written report or presentation for others to learn and replicate.
- Modify scientific method steps if direct experimentation is not possible, using simulations or models if needed.
- The main goal is to discover cause-and-effect relationships through evidence.
Key Terms & Definitions
- Scientific Method — a systematic approach to investigating questions using experiments.
- Hypothesis — a testable, educated guess predicting an experiment’s outcome.
- Independent Variable — the factor intentionally changed in an experiment.
- Dependent Variable — the factor measured as an outcome.
- Controlled Variable — factors kept constant to ensure a fair test.
Action Items / Next Steps
- Practice the scientific method by designing and conducting your own experiment.
- Visit www.sciencebuddies.org for project ideas and more information.