1. Not just for scientists!
The Scientific Method
Not just for scientists!
Adapted from

2. What is it?
The scientific method is a logical sequence of steps that people use to identify, test, and answer a problem.
It is broken down into six steps:
State the problem.
Form a testable hypothesis.
Design an experiment.
Collect and analyze data.
Draw conclusions.
Communicate results.
Have students fill in notes in each appropriate box on the SM Cheat Sheet

3. Taking a closer look… Choosing a question or problem to solve:
Make sure it’s realistic and that you can gather the necessary resources.
When possible, choose a topic that really interests you.
Your question must include both a manipulated (independent) variable and responding (dependent) variable.
Safety first!
Make it new and interesting to YOU!
Tip 1-Investigating the effect of lemon juice on the growth of bread mold is a lot more realistic than trying to conduct an experiment on the effectiveness of a certain type of tile on the space shuttle's outer hull.
It would be easy for you to find the materials needed to see how lemon juice affects bread mold. You could probably get the materials needed to conduct such an experiment from home - you would just need some lemon juice and bread. You probably wouldn't be able to conduct hands-on tests with the space shuttle because you don't have one easily accessible.
Tip 3 - A manipulated (or independent) variable (or MV for short) is something that you intentionally change in your experiment.
A responding (or dependent) variable (or RV for short) is something that changes as a result of what you intentionally changed.
Tip 4 - You may not investigate a question that would involve putting yourself, someone else, or an animal in any danger. Be sure to think your question through by asking yourself what materials or actions would be involved in completing the experiment. If your experiment would require dangerous chemicals, tools, apparatus, or procedures, you should think of another question.
Tip 5 - Pick a question that does not have a commonly found answer. In other words, the question should not be something that you could look up in an encyclopedia or on the Internet to find the answer. It needs to be something that you must investigate through experimentation to find the answer. Your question should not be answered with a simple "yes" or "no."

4. Examples of good questions…
How does the size of a wheel affect the speed of a Hotwheel’s car?
How does color affect people’s food choices?
How does age affect a person’s reaction time?
How does the amount of water affect the growth of a plant?

5. Checkpoint! How are rainbows formed? Good question. Unsafe question.
Difficult to get materials.
No manipulated and responding variables.
Correct answer is D.
Read the question. Decide whether the question is a good one for a middle school student to investigate or not. Raise the letter of the answer you believe is correct.

6. How does eating food affect a person’s growth?
Good question.
Answer is already known.
Difficult to get materials.
Unsafe question.
Correct answer is B.
Read the question. Decide whether the question is a good one for a middle school student to investigate or not. Raise the letter of the answer you believe is correct.

7. In a crash, how does the speed of the train affect the amount of damage to a non-moving car?
Good question.
Question is not interesting.
Difficult to get materials.
No manipulated and responding variables.
Correct answer is C.
Read the question. Decide whether the question is a good one for a middle school student to investigate or not. Raise the letter of the answer you believe is correct.

8. How does the type of liquid affect plant growth?
Good question.
Unsafe question.
Difficult to get materials.
No manipulated and responding variables.
Correct answer is A.
This is a good question to investigate because it is safe, interesting, contains a manipulated and responding variable, is inexpensive, and is probably something you would not find in an encyclopedia.

9. Taking a closer look… Creating a testable hypothesis:
“I predict that…”
Include a statement that shows cause and effect.
It must address the manipulated and responding variables.
Right or wrong does not matter!
Tip 2 - An "If...then..." statement is one that shows a cause and an effect relationship. For example, "If a plant is given acidic liquids, then the plant's growth will decrease." In this hypothesis, there is a cause (acidic liquid) that produces an effect (decrease in plant growth).
Tip 3 - The cause and effect in your hypothesis are related to the manipulated and responding variables in your question. For example, look at this question: "How does the type of music affect a plant's growth?" The type of music can be changed intentionally, so it is the manipulated variable. The plant's growth may change as a result of the type of music, so it is the responding variable. Your hypothesis must include an MV and RV: "I think that if a plant is exposed to classical music (MV), then it will grow very fast (RV)."
Tip 4 - At the end of the experiment you will find out whether your hypothesis was right or not. As a scientist, you should understand that it is not important that you "got it right." It is more important that you learned something about your topic. Don't get hung up on having the right answer.

10. Examples of good hypotheses…
I predict that if a student reviews their science notes 30 minutes each day, their science test scores will improve.
I predict that the longer the mealworm the faster it will travel in a given length.
I predict that if a plant receives too much water it will become unhealthy and die.

11. Checkpoint! Q - How does color affect a person’s food choices?
H – I predict that if a person sees a red sweater, they will choose it over one of a different color.
“I predict that…” is missing.
There is no cause and effect statement.
Does not answer the question.
Good hypothesis.
Correct answer is C.
Read the question. Decide whether the question is a good one for a middle school student to investigate or not. Raise the letter of the answer you believe is correct.

12. Q - How are paper towel brand names and absorbencies related?
H – If the brand name is expensive then its absorbency will be higher.
“I predict that…” is missing.
There is no cause and effect statement.
Does not answer the question.
Good hypothesis.
Correct answer is A.
Read the question. Decide whether the question is a good one for a middle school student to investigate or not. Raise the letter of the answer you believe is correct.

13. Q - How does age affect a person’s reaction time?
H – I predict that if a person is older, they can react.
“I predict that…” is missing.
It does not include a MV and RV.
Does not answer the question.
Good hypothesis.
Correct answer is B.
Read the question. Decide whether the question is a good one for a middle school student to investigate or not. Raise the letter of the answer you believe is correct.

14. Q - How does the size of a wheel affect the speed of a Hotwheel car?
H – I predict that a car with larger wheels will go slower than a car with smaller wheels.
“I predict that…” is missing.
There is no cause and effect statement.
Does not answer the question.
Good hypothesis.
Correct answer is D.
Read the question. Decide whether the question is a good one for a middle school student to investigate or not. Raise the letter of the answer you believe is correct.

15. Good morning… Pass back graded work (2 volunteers please)
Review Vocabulary Terms and SM Cheat Sheet Steps 1 and 2 quietly
Step #3 of Scientific Method:
Design an Experiment (need Cheat sheet)
Why common measuring system?
Metrics experts

16. Metrics Experts
Working in rows: read your purple book pages to learn about your assigned topic
Work together to create 1 page describing the topic
Be prepared to teach your topic to the class using the document camera

17. Taking a closer look… Designing an experiment:
Carefully decide what your constants will be.
Decide what materials you will need.
Decide how you will measure your constants and your manipulated variable.
List all procedures in order.
Tip 1 - Before you do any designing, you must decide what variables will need to be controlled or kept the same in your experiment. Remember that you can change only one variable intentionally - the manipulated variable. Everything else must remain the same in your experiment or your results will be not be valid.
Tip 2 - Once materials are listed, ask yourself how you will measure (or operationally define) your materials and results. If you are measuring length, use millimeters, centimeters, or meters. If you are measuring weight, use milligrams, grams, or kilograms. To measure volume, you must use milliliters or liters. Temperature must be measured in degrees Celsius. All measurements must be Metric.
Tip 3 - Before you begin experimenting, you must ask yourself how you will operationally define your variables. In other words, how will you measure them so that they can be put into number or quantitative terms?
If you are measuring growth of a plant, then how will you define "growth?" Is it the height of the plant (measured in millimeters or centimeters)? Is it the weight of the plant (grams)? In your experiment, does growth refer to the size of the leaves? Whatever you want growth to be in your experiment must be clearly defined ahead of time. Write down all measurements you will use to define each variable operationally.
Tip 4 - Once you decide which variables need to be controlled, what materials you will need, and how you will operationally define your variables, you must list all the procedures you need to complete in order to conduct the experiment.
Starting from the very beginning, list all of your procedures in order. Include many details. Include how you will control variables. Write down how you will measure your results.
Your finished procedures should be detailed so that anyone who wants to duplicate your experiment can do so simply by following your list.

18. Example of designing an experiment:
Question – How does the amount of water affect plant growth?
Hypothesis – I predict that if a plant receives too much water it will become unhealthy and die.
Experiment Design:
Constants: type & age of plant, type & size of pot, amount & types of soil, amount of sunlight, type & time of water provided, time of day growth is measured.
Manipulated Variable: ?
Materials needed: 5 identical pots, soil, 5 identical bean seeds, water, graduated cylinder, sunny window.
Measuring data: Soil will be measured in grams, water will be measure in milliliters, growth will be measured in centimeters, growth will be measured from the soil to the tallest part of the plant.

19. Example of procedures:
Measure 300 g of soil and pour into plastic pot. Repeat for each pot.
Place 3 bean seeds on the top of the soil in each pot.
Measure 100 g more of soil and sprinkle over beans. Repeat for each pot.
Place all 5 pots in a sunny window. All pots should be positioned to receive the same amount of light.
Label each pot with a number using a sharpie. Pots will be numbered
Measure 10 ml of water and pour into pot #1. Measure 20 ml of water and pour into pot #2. Put 30 ml in pot #3, 40 ml in pot #4, and 50 ml in pot #5.
Record date in log book along with water measurements for each pot.
Check plants at 4pm every day. Measure and record height (in cm) for each plant daily.
Which of these procedure #’s contains the mv?

20. Checkpoint! Question: How does color influence people's food choices?
Hypothesis: I predict that if people see a red cookie, then they will choose it over any other color of cookie offered to them.
Controlled variables: Type of cookie, color of cookies, age and gender of people being offered cookies, size and shape of cookies, temperature of cookies, "doneness" of cookies.
Correct.
One of the variables listed should not be included.
More variables need to be controlled.
These are not controlled variables.
Correct answer is B.
The color of the cookies should not be controlled. The color of the cookies is the manipulated variable and must be changed. Click the right arrow below to continue.

21. Question: How does color influence people's food choices?
Hypothesis: I predict that if people see a red cookie, then they will choose it over any other color of cookie offered to them.
Materials: sugar, flour, milk, butter, food coloring (blue, red, yellow, and green), oven, cookie sheet, cookie cutter, bowls, spoons, spatula, measuring cups, serving tray, 10 girls who are years old.
Correct.
Some materials listed are not necessary.
Some materials are missing.
Material list does not fit the problem or hypothesis.
Correct answer is A.

22. Question: How does color influence people's food choices?
Hypothesis: I predict that if people see a red cookie, then they will choose it over any other color of cookie offered to them.
Procedures:
Mix the flour, sugar, milk, and butter according to the recipe.
Cut out the cookies using a round cookie cutter. Be sure the cookies are exactly the same size and shape.
Bake cookies according to the recipe and cool for 1 hour.
Place 5 of each color of cookie on a serving tray.
Offer guests cookies. Serve the cookies to one guest at a time, and replace the colors as they are taken.
Count how many cookies of each color are taken.
Record data.
Correct.
There are unnecessary steps included.
One of the steps is repeated.
A step has been left out.
Correct answer is D.
There is no step that tells how to make different colors of cookies. Click the right arrow below to continue.

23. Taking a closer look… Collect and analyze data:
Always keep variables in mind and follow your procedures.
Organize your raw data in a table.*
Use your data table to create a graph for your conclusion. (More to come!)
Tip 1 - Don't forget that the only variable that you are changing in your experiment is the manipulated variable. Everything else must remain exactly the same.
Tip 2 - Raw data is the first information you get as you make observations during your experiment. For example, if you were charting plant growth, you might find that on the sixth day of the experiment, the plant has grown to a height of 1 cm. On the next day, it is 1.5 cm. Then the following day the plant is 1.7 cm. All of this information is raw data. It needs to be kept in your log book. Tip 4 - Once you decide which variables need to be controlled, what materials you will need, and how you will operationally define your variables, you must list all the procedures you need to complete in order to conduct the experiment.
Starting from the very beginning, list all of your procedures in order. Include many details. Include how you will control variables. Write down how you will measure your results.
Your finished procedures should be detailed so that anyone who wants to duplicate your experiment can do so simply by following your list.

24. Data Table Example – The effects of water on plant growth.
Manipulated Responding Variable Variable Amount of Water (ml) Height of Plant (cm)
A data table is the easiest way you can record your information. It looks like the diagram below. The manipulated variable is always placed on the left side of the table, and the responding variable is always located on the right side. When you get your data, simply put it into the table.
When you record data in a table, be sure to list the manipulated variable numbers in the left column from smallest to largest. Also, the numbers for the manipulated variable should fall into a pattern (for example, by ones - 1, 2, 3, 4, 5; by fives - 5, 10, 15, 20, 25; by hundreds - 100, 200, 300, 400, 500).

25. Checkpoint! Chart Correct.
Manipulated variable does not have a pattern of numbers.
The MV are out of order.
The MV and RV are on the wrong sides.
Correct answer is D.
On the following pages are some data tables. Look at each table carefully and decide whether it contains correct information.

26. Chart
Correct.
Manipulated variable does not have a pattern of numbers.
The MV are out of order.
The MV and RV are on the wrong sides.
Correct answer is C.
On the following pages are some data tables. Look at each table carefully and decide whether it contains correct information.

27. Chart
Correct.
Manipulated variable does not have a pattern of numbers.
The MV are out of order.
The MV and RV are on the wrong sides.
Correct answer is A.
On the following pages are some data tables. Look at each table carefully and decide whether it contains correct information.

28. Chart
Correct.
Manipulated variable does not have a pattern of numbers.
The MV are out of order.
The MV and RV are on the wrong sides.
Correct answer is B.
On the following pages are some data tables. Look at each table carefully and decide whether it contains correct information.

29. Taking a closer look… Collect and analyze data(Graph):
MV on the x axis and the RV on the y axis.
Use a pattern of numbers for each axis.*
Include units (m, l, g) and a title.
Plot your data.
Tip 1 - Take the raw data from your data table and use the exact same numbers in your graph. Remember that you must keep the number from the manipulated variable side with its counterpart on the responding variable side. These two matching numbers are called ordered pairs, and they cannot be separated from one another. They always go together.
Tip 2 - The horizontal axis (or x axis) on a graph shows the manipulated variable. Therefore, you must write your MV just below the x axis on your graph. The vertical axis (or y axis) represents the responding variable in your experiment. Write your RV to the left of the y axis on the graph.
Tip 3 - Once you label the manipulated and responding variables on your graph, you must also include how you will operationally define each of these variables. For example, if you are measuring length, you might operationally define the variable with millimeters, meters, or kilometers. Be sure to use abbreviations when operationally defining variables, and only use Metric measurements.
Tip 4 - This pattern must cover the smallest and largest numbers in your manipulated and responding variables. A pattern is a series of numbers that adds an equal amount for each successive number. Look at the examples of number patterns below.

30. Pattern of numbers Look at the data table below.
What would be a good pattern for the
MV numbers? How about the RV numbers?
A good pattern for the manipulated variable would be (2, 4, 6, 8, 10). The numbers are already arranged by twos, so this part is easy. A good pattern for the responding variable might be (12, 14, 16, 18, 20). This pattern covers the smallest number on the RV side (14) and the largest number (18).

31. Plot the Data
To plot data, start with the x axis and find your first number under the MV column on your data table. In the table below, the first number is 2. Then, on the y axis, find the corresponding number from the RV column on your data table. In the table below, the corresponding number is 14. Draw one imaginary line up from the x axis and another imaginary line to the right on the y axis until the two lines intersect. The point of intersection is where you should plot your point. Repeat this process for all of your ordered pairs on the data table.

32. Finished Example
The title of your graph must relate directly to your manipulated and responding variables. It is a good idea to include both the MV and RV in the title.

33. Checkpoint! Graph Correct. MV and RV are labeled on the wrong axis.
Number pattern is incorrect.
Data not plotted correctly.
Correct answer is C.
The number pattern for the responding variable is incorrect. It should be written using a pattern of ones (1, 2, 3, 4, 5).

34. Graph Correct. MV and RV are labeled on the wrong axis.
Number pattern is incorrect.
There is no title included.
Correct answer is D.

35. Graph No units of measurement for MV & RV.
MV and RV are labeled on the wrong axis.
Number pattern is incorrect.
There is no title included.
Correct answer is B.
The manipulated variable should be written on the x axis, and the responding variable should be written on the y axis.

36. Graph No units of measurement for MV & RV.
MV and RV are labeled on the wrong axis.
Number pattern is incorrect.
There is no title included.
Correct answer is A.

37. Graph Data plotted incorrectly. Correct. Number pattern is incorrect.
No units of measurement for MV & RV.
Correct answer is A.
The last ordered pair has been plotted incorrectly.

38. Taking a closer look… Drawing conclusions:
Restate your problem and hypothesis.
Summarize your procedures.
Explain how the MV affected the RV. (What does the graph show?)
Explain whether or not the results supported your hypothesis.
If not, why?
Future experiments.