The Scientific Method

The Steps Ask a question Do background research Formulate a Hypothesis Test your hypothesis Analyze data to draw a conclusion Communicate the results

1. Asking questions -the question has to be testable Good example: Does a toy car roll faster on tile floor or wood floor? Bad example: Which type of toy car is the best?

Let’s Practice If someone wanted to figure out which type of toy car was faster, what is a testable question we can write for this experiment?

Try it yourself. In your notebook write two testable questions.

2. Do Research Someone may have already done an experiment on the topic Someone may have done a similar research project that can help yours Sometimes you can find out how to go about the experiment, and how NOT to.

3. Formulate a Hypothesis -Where you make a prediction or educated guess. -Always an If/then statement. -If I test _______ then __________ will happen.

Turning a question into a hypothesis Q: Which type of surface will create the most friction? A: If I test a toy car on different surfaces, then it will roll the furthest on wax paper.

Let’s write a hypothesis ___________________________________________________________________________ ___________________________________________________________________________ ____________________________________________________________________________

Try it yourself. Formulate a hypothesis around this testable question. Which liquid will help a plant grow the most, sugar water, soda, or plain water?

4. Testing -Independent Variable - What you change -Dependent Variable - What you measure -Constant - What has to stay the same. *not every experiment requires a constant

Why do you need constants? So you know that only the independent variable caused the results.

Data Collection Data is always stored in a data table. The data table has the independent variables down the left side, and the trial numbers across the top. The rows go left to right, and columns go top to bottom. Always include an average column as well.

Data Tables

5. Analyze data Data in data tables are always converted to graphs Not all data is numbers Qualitative data - based on qualities such as color or taste or smell. Quantitative data - based on the quantity or the numbers.

Write these in your notebook and label Quantitative or Qualitative The temperature of the substance __________ The distance the object travelled ___________ The state of matter an object is in __________ The color the object turns _________________ The amount of the substance gathered ______ The type of substance gathered ____________

Bar Graph or Line Graph? If you have two sets of Quantitative data on your data table, you’ll want to make a line graph. If you have one set of Quantitative and one set of Qualitative, you’ll make a bar graph.

Bar Graph or Line Graph?

How to graph

6. Share the information Experiments are shared so that other scientists can look at it. Scientists may run the same experiment to see if they have the same results.

Let’s Discuss In your notebook, write 2-3 sentences on why you believe we use the scientific method and why it is (or isn’t) important.

Share with your partner what you believe Share with your partner what you believe. Your ideas may be very, very different.

Now it’s your turn On your own, plan an experiment that you can execute at home. Some ideas include: What flavor of mentos creates the tallest explosion of diet coke? What type of laundry detergent removes the most grass stains? Which type of soda is the most corrosive? How many drops of water will fit on different types of coins?