The Practice of Science

1. The Practice of Science Designing an Investigation

2. The Process of Science • There’s no such thing as THE scientific method! • It’s more like “methods that are scientific” or “a scientific process” • The process of searching for explanations about the natural world doesn’t always follow a set of step-by-step procedures/rules.

3. The Process of Science • NOT ALL scientific knowledge comes from experiments. • Controlled experiments are only one type of scientific investigation • That said, your science fair project should be a controlled experiment (unless you are working with Mr. Rodriguez on a different type of investigation).

4. SCIENCE FAIR: Choosing a Topic • Choose a topic to investigate. • Make sure it is interesting to you. • Make sure you have the resources (tools, ability, time) to investigate it. • Make sure there is an adequate research base available to you. • Make sure there are answerable questions that are relevant to your topic. • Our class project topic will be…

5. Soda & Mentos Reaction

6. Diet Coke & Mentos Fountain

7. SCIENCE FAIR: Research Question • Refine your topic into a testable question. • A testable question is one that can be answered with data you gather. • Identify variables that may have an impact on the original set of conditions. Choose one of these variables to test. • Effective research questions often identify both the independent (test) variable and the dependent (outcome) variable, ex: How does “x” affect “y”?

8. SCIENCE FAIR: Variables • The identification and control of variables is what characterizes a controlled experiment. • Independent Variable • Only ONE • Factor being tested/manipulated to see its impact • Dependent Variable • Only ONE • Factor being observed/measured to see how it is affected • Constants (Controlled Variables) • All other factors must be kept the same so they don’t influence the outcome

9. Soda and Mentos: Research Question • Brainstorm some testable questions for our soda and Mentos investigation. • Think of variables that may have an effect on the reaction: DEPENDENT? • Height of Spray • Duration (Time) of Spray • Amount of “Fizz” INDEPENDENT? • Brand/Type of Soda/Mentos • Number of Mentos • Temperature of Soda/Mentos

10. SCIENCE FAIR: Researching Your Topic • Search for information relevant to your topic to generate possible answers. • Try to consider every reasonable alternative • Use your research to narrow down possible explanations • Hypothesis vs. Prediction • A hypothesis is a testable explanation of the phenomenon. • A prediction is a statement of the expected outcome. • Ex) If (yourhypothesis) is true, then (your prediction) will be observed.

11. Soda and Mentos: Research • Have others already attempted to answer this question? • What information might be helpful to answer this question? • What causes the reaction? • What ingredients are present? • How will the environment affect the reaction? • Where can we get this information? • Mythbusters episode • Internet research

12. SCIENCE FAIR: Planning Your Investigation • Plan out a timetable for your investigation. Make yourself deadlines and stick to them! • Design your investigation. • What type of investigation? How can you test your hypothesis? • What data will you need? • How/What will you measure/observe? • How will the data help you answer the question? • How will you control variables (if necessary)? • What materials will you need?

13. SCIENCE FAIR: Planning Your Investigation • Data vs. Evidence • Data consists of information you gather during your investigation • Observations and/or measurements • Evidence is data that has been analyzed and interpreted in support of a claim • Not all data will be evidence… • Scientific Confirmation • Ensures consistent and predictable results through repetition and replication • REPETITION – multiple trials • How do you know when you have enough trials? • Your data is consistent and predictable • REPLICATION – another scientist is able to duplicate your investigation with similar results

14. Soda and Mentos: Investigation Planning • What type of investigation? • What data will we need? • How/What will we measure/observe? • How will the data help us answer the question? • How will we control variables? • What materials will we need?

15. SCIENCE FAIR: Analysis • How can we learn from the investigation? • What can we learn from the investigation? • Think of ways to report your evidence. • What data is important? How can you highlight that importance? What can you COMPARE? • What relationships exist? How can you show them?

16. SCIENCE FAIR: Conclusions • What conclusions can be drawn? • Scientific CLAIMS must be supported by EVIDENCE. EVIDENCE must be JUSTIFIED with accepted scientific principles. • Note the word “supported” above…how is this different from the word “proven”? • Scientific explanations are TENTATIVE (open to change). • There is NO SUCH THING as “proof” in science. Scientific theories cannot be proven (despite what you may hear from actual scientists or the media). • We say “The results support…” or “The data suggests…” rather than “…has been proven”.

17. Soda and Mentos: Analysis • What data is important? • How can we highlight its importance? • What relationships exist? • What can we compare? • Does the data show relationships between the variables? • How can we show them?

18. Soda and Mentos: Conclusions • What conclusions can be supported by our data? • What data do we have to draw from? • How does that data support our conclusion? • Why are we able to use that data to support our conclusion? How can we use scientific concepts to explain the relationships?