1. The Scientific Method

2. What is the Scientific Method??
The basic steps that scientists follow to uncover facts and solve scientific problems
It’s a plan for solving a problem!
Gathering, organizing, and communicating data

3. What are the steps? Make an Observation Ask a Question
Do Background Research
Develop a Hypothesis
Experiment: Test your Hypothesis
Analyze the Data
Conclusion (report and share)

4. Step 1: Observation Everything starts out with an observation
What is an observation? Anything you perceive with your senses
Ex. The sun is bright.
Sugar tastes sweet.
Sandpaper feels rough.

5. What can you observe about these two fish in their tanks?

6. Step 2: Form a Question Ask a question based on your observations.
Develop a question that can be solved through experimentation!
Can you think of a question based on your observation of the two fish?

7. Step 2: Form A Question
Does the size of a fish’s tank affect how big it grows?
We observed that the fish with the bigger tank was larger than the fish with the smaller tank. Is this a coincidence?

8. Step 3: Do Background Research
Research your subject. Collect the knowledge you need to know to perform your experiment.
Your research will help you to form your hypothesis.

9. Step 4: Develop a Hypothesis
What is a hypothesis?
An educated prediction or the answer of a problem or question
Based on research and prior knowledge

10. Step 4: Develop a Hypothesis
A hypothesis should sound like this..
“I think ___________________ because __________________________.”
“If ____________________, then ___________________ because ________________.”
You can fill in the “because statement” using your background research!

11. Step 4: Forming a Hypothesis
What is your hypothesis for our question about the fish?
Question: Does the size of a fish’s tank affect how big it will grow?
Remember to use “I think…. Because……” or “If…. Then… because…”
Use our background research to justify your prediction!

12. Step 5: Experiment (Test your Hypothesis)
What is an experiment?
This is how you test your hypothesis.
Develop a set of steps you can repeat that will allow you to observe and collect data to test your hypothesis.

13. Step 5: Testing your Hypothesis
An experiment includes variables.
A variable is a quantity that is measured or changed during the experiment.
There are different kinds of variables:
Independent variable
Dependent variable
Control
Constant

14. Step 5: Testing your Hypothesis
Independent variable: What you are changing in the experiment
Dependent variable: the outcome caused by changing the independent variable (this is what will be measured)
Control: The “normal group” used for comparison (If we were testing adding things to the fishes’ water, the control would be a fish tank with plain water)
Constant: stays the same from one experiment to the next

15. Step 5: Testing your Hypothesis
For our experiment…
Some types of fish grow bigger than others. How should we deal with this?
Use only one type of fish in our experiment.
We are trying to see if the size of the fish tank affects how big the fish will grow.
What should we change? What should we have different measurements for? The size of the fish tank
What should change depending on the size of the fish tank? The size of the fish
How can we measure the growth of the fish during their time in our tanks? Measure at the beginning, measure at the end

16. Step 5: Testing your Hypothesis
Let’s identify the variables in our experiment.
Independent variable: What are we changing in the experiment? The size of the tank
Dependent variable: What will change depending on our independent variable? The size that the fish will grow to
Constant: What will stay the same in every experiment? The type of fish we use

17. Step 6: Collect and Analyze the Data
Observations, information, and data are collected from the experiment.
Organize the data (measurements, observations) and perform any calculations needed
Interpret the data you gathered from your experiment

18. Step 6: Collect and Analyze the Data
Use your data to construct charts or graphs.
You can use the charts or graphs to SEE trends in your data.
Dependent Variable
Independent Variable

19. Step 6: Collect and Analyze Data
How would you graph the data from our fish experiment?
1. Identify the Independent Variable and place it on the x axis.
2. Identify the Dependent Variable and place it on the y axis.
3. Plan a scale for your graph. Label the graph.
4. Place points for each Independent Variable on its Dependent Variable measurement.
5. Draw a line to smoothly connect the points.

20. Step 6: Collect and Analyze Data
Pretend that we collected these results from our fish experiment.
Tank Size
Fish Start Size
Fish End Size
Total Growth
1 L
10g
14g 4g
2 L
12g
18g 6g
3 L
11g
20g 9g
4 L
21g
5 L
13g
25g

21. Step 6: Collect and Analyze Data
We can use our data to create a graph.
Growth of Fish (g)
Tank Size (L)

22. Step 6: Collect and Analyze Data
What does this graph show us?
Growth of Fish (g)
Tank Size (L)

23. Step 7: Conclusion Does your data support your hypothesis?
If YES… You just made a scientific discovery!
If NO… Make a new hypothesis or revise your experiment and test again!

24. Step 7: Conclusion (and Sharing)
Summarize your results and answer your question.
Were there any possible sources of error?
Maybe one of our fish got sick and couldn’t grow normally.
Does your data support your hypothesis? Why or why not?

25. That’s all!