1. SCIENCE FAIR Mini-Lesson #4
Identifying Variables, Writing a Hypothesis, Listing Materials & Outlining the Procedure

2. DO NOT WRITE IN OR ON THE BLUE FOLDER!
Let’s Begin……
On your desk you have some questions to answer. Read “Variables In a Science Fair Project,” “Hypothesis,” “Materials” and “Experimental Procedure” in the blue folder and answer the questions. You will have 30 minutes to find all of the answers.
Remember:
DO NOT WRITE IN OR ON THE BLUE FOLDER!

3. Let’s Answer Those Questions…
1. What is a variable and what are the 3 variables found in any experiment?
2. How many variables should a scientist change in a good experiment?
Any factor, trait, or condition that can
exist in differing amounts or types. In any experiment there exists the independent variable, the dependent variable and controlled variables
One

4. 3. Contrast independent variables and dependent variables
4. What is the purpose of a control variable?
An independent variable is what the
scientist changes but a dependent variable
is what a scientist is measuring
Conditions that a scientist wants to keep
constant so they cannot affect the outcome
of the experiment

5. 5. What is a hypothesis?
6. Why did you write your research paper first?
7. Is it bad if your experiment disproves your hypothesis?
An educated “guess” about how things work
To give you background knowledge to make a good hypothesis
No, in fact very few scientist have EVER
been correct on their very 1st try.

6. 8. What is an experimental procedure and why should it be detailed?
9. Contrast the control group and the experimental group
A step-by-step recipe for your science experiment. It should be detailed so others could replicate it and get the same results.
The experimental group are the trials where you change the independent variable. The control group are the trials where the independent variable is left in its’ natural state and basis of comparison (what is normal.)

7. 10. Explain why some experiments will not have a control group.
11. Explain why it is important to have a very detailed materials list before you perform your experiment.
Some experiments have independent
variables that do not have a natural/normal state
To make sure you have everything on hand when you need it.

8. PRACTICE SCENARIO: A student would like to test the effect of varying the amount of water on the growth of red roses. To test this, a student grew 3 identical types of red roses in 2000mL plastic buckets. One with a normal, recommended amount (50mL) of water, one rose given twice as much water as normal and one rose given three times the recommended amount of water. They were given the same amount of sunlight and type of tap water. The plants were also given 60g of MiracleGro Plant food 1x/week. Every day the overall height of each plant was checked and recorded.

9. What is the independent variable?
What is the dependent variable?
Why were all other variables kept the same?
amounts of water
rose plant growth
To make sure only water caused the
plant growth.

10. d. After writing a research paper, the student in the above scenario found out that more water will lead to an increase of rose growth, write an appropriate hypothesis for the student. You must write this as an if/then statement – the IF part is followed by the independent variable, the THEN part is the dependent variable PLUS THE PREDICTED OUTCOME based on RESEARCH.
If more water than normal is added
to the rose plant, then the rose plant will
grow more than normal.
** NOTICE NO I’s in the written hypothesis!!!**

11. e. Which plant(s) would be considered the control group?
f. Which plant(s) would be considered the experimental group?
Those grown with a normal amount
of water
Those grown with a non-normal amount of water

12. g. Sort the pattern puzzle into the appropriate steps for the experimental procedure. Once you have sorted the steps, write down what was included in the procedure that you should also include in yours.
- A step-by-step list of everything that
must be done in the experiment. Within that recipe there should be:
Identification of the independent and dependent variables and how they will be changed/measure
Identification of experimental and control (if applicable) groups

13. What the controlled variables are and how they will be maintained
How many times the experiment will be repeated (plants need 1x – sports/short pH experiments need multiple test to ensure accuracy)

14. STEP 1: Three red rose plants of the same
species were planted in the same 2000mL
Container.
STEP 2: The first red rose plant is considered
the control group and given the recommended
50mL of water every day for 4 weeks.

15. STEP 3: The second and thirds rose plants are
the experimental groups. The amount of water
in these rose plants will be varied as the
independent variable. Therefore, the second
rose plant is given 100mL of water every day
for 4 weeks and the third rose plant is given
150mL of water every day for 4 weeks.
STEP 4: The dependent variable is the amount
of rose plant growth. This will be measured in
centimeters using a ruler everyday of the
4 weeks.

16. STEP 5: To control all other conditions, the plant’s growth will be measured every day at 3pm. Water will be given to each plant at 7am every day. The water will be of the same type – tap water. Each plant will be exposed to the same amount of light from 7am to 7pm using sunlight. Each plant will be given 60g of MiracleGro plant food on the first day of every week at 3pm.

17. h. Write a DETAILED materials list including amounts of item is SI units that were used
3-red rose plants
mL buckets of the same shape, color, etc.
720g of MiracleGro plant food
ruler
tap water readily available for 4 weeks
sunlight
measuring cup (in milliliters)
scale (used to measure milligrams)
pen
lab notebook