The Practice of Science Designing an Investigation

There’s no such thing as THE scientific method! 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.

NOT ALL scientific knowledge comes from experiments. 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).

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…

Soda & Mentos Reaction

Diet Coke & Mentos Fountain

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”?

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 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

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: INDEPENDENT? Brand/Type of Soda/Mentos Number of Mentos Temperature of Soda/Mentos DEPENDENT? Height of Spray Duration (Time) of Spray Amount of “Fizz”

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 (your hypothesis) is true, then (your prediction) will be observed.

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

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?

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

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?

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?

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”.

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?

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?