The Scientific Method The Scientific Method Used by

The Scientific Method

The Scientific Method Used by scientists to support or _______ a theory (“how do you know? ”) Only accepted way to do this! Steps are not always followed in the same order.

The Scientific Method involves 7 steps: Observation _____ Hypothesis Experiment/Research Analyze the Results ______ Communicate the Results

Which steps of the Scientific Method are not mentioned in this video? __________________________

The Scientific Method Observation- You ____ something in the material world, using your senses “Hmm…I wonder why”…. AH—Look at this!

The Scientific Method Question- You ask a question about what you observe. State the ____ or question. “Which color of light do plants prefer? ”

The Scientific Method Hypothesis- You predict what you think the answer to your question might be. You MUST ______ first “Plants prefer the color green, because they are green themselves. ”

The Scientific Method Experiment - You design a way to test whether your hypothesis is correct. Research – Sometimes testing a hypothesis requires many more detailed ________. Must be measurable (have numbers!) Record (write down) and analyze

The Scientific Method Analyze the Results Record your data carefully and create ______ and graphs to make the results clear.

The Scientific Method Conclusion After completing the experiment and analyzing the results, you write up “your _______” of the experiment. What happened? Was your hypothesis supported or not? Why did this happen? What did you learn? What would you do next?

The Scientific Method Communicate the Results Share your _____ with the world. This allows others to learn from your work and test your hypothesis further. (Besides, you can’t win that Nobel prize if no one knows about your discovery!)

Why is it important to have a control group? ____________________________________________

The Lab Report Example Title (centered and underlined) Question: What color of light do plants prefer? Hypothesis: Plants prefer green light because they themselves are green.

Prediction: Here is your if/then statement. If I put plants under different colored lights, then the plant under the green light will grow the most. ______ your experiment.

Independent, Dependent and Controlled Variables The independent variable is the variable that you decide upon. You are trying to see if changing it affects the results. In this case the _______is the independent variable. The dependent variable is what should change because of the independent variable. It depends on the independent variable. In this experiment it is the _____________. It is the thing we measure.

Whoa! Hold On! What if the plants aren’t all the same kind? ” What if I forget to water some of them for a couple of days? What if I have one next to a window? These are all examples of variables that need to be ______: CONTROLLED VARIABLES (the book calls them constants). They are things that can change in an experiment but wouldn’t be fair if they were different for each group.

Controlled Variables (Controls) The controlled variables are things that must all stay the same or you’ll never know if they were the reason for the results you got. Maybe the plant grew taller because it got more water not because of the color of the light. Not ____ them can really mess up your experiment! Amount of water, kind of plant and a dark room are some of your controlled variables.

Setting up your Experiment Control Group (different from controlled variables) This group would have white light. It is the group where you _____ control the color so you can compare your experimental group to it. 1 Control group of at least 2 plants

Experimental Group This is the group that you _______ your independent variable to. Each sub-group of at least 2 plants (more is better, can you guess why? ) would have a different color light. Example: 1 group of plants for red light, 1 for blue, and 1 for green.

Materials: . 4 groups of at least 2 plants Colored lights: white, red, green, blue Ruler 16 of the same size pots 5 bags of the same soil type Water Data Table to record measurements.

Procedures: 1. Place 4 groups of plants in a dark room. 2. Measure the height of each plant before beginning the experiment 3. Place a different colored bulb over each plant. 4. Allow each plant to grow undisturbed for two weeks, remembering to water all equally. 5. Measure the ending height of each plant, and calculate how much each grew.

Results: Average Height of plants in centimete rs Light Color

Conclusion: The results did not support my hypothesis. The plants grew taller (over 5 cm) under the blue light. They actually grew the least (2 cm) under the green light. Light color does affect plant growth and blue light provides the most energy. After doing more research, I discovered that plants appear green because they reflect green light to our eyes. If they reflect green light they can’t use it for photosynthesis. Next I would like to research the affect of light intensity on plants.

Were You Paying Attention 1. 2. 3. Every hypothesis must include the word “______” to show that it is an “educated” guess with some observations or scientific understanding to back it up. A _______ should describe your experiment and what you expect the outcome to be if your hypothesis is correct. The ______ variable is the thing you are changing to see if changing it makes a difference in the outcome.