1. Identify the Controls and Variables
Ms. Nilmalgoda

2. Smithers thinks that a special juice will increase the productivity of workers. He creates two groups of 50 workers each and assigns each group the same task (in this case, they're supposed to staple a set of papers). Group A is given the special juice to drink while they work. Group B is not given the special juice. After an hour, Smithers counts how many stacks of papers each group has made.
Group A made 1,587 stacks,
Group B made 2,113 stacks.

3. Independent (Manipulated) Variable
Identify the:
Control Group
Group B is the control group, because they are not given the special juice.
Independent (Manipulated) Variable
The independent variable is the special juice.
Dependent (Responding) Variable
The dependent variable is the productivity of the workers, measured by how many stacks of papers they staple.

4. 2. What should Smithers' conclusion be?
Smithers should conclude that the special juice does not, in fact, increase the productivity of the workers. It instead appears to make them staple slower.
3. How could this experiment be improved?
Ex. Workers could be given different tasks or different amounts of juice, both groups can be tested for productivity without juice before giving one group the independent variable, etc.

5. Homer notices that his shower is covered in a strange green slime
Homer notices that his shower is covered in a strange green slime. His friend Barney tells him that coconut juice will get rid of the green slime. Homer decides to check this out by spraying half of the shower with coconut juice. He sprays the other half of the shower with water. After 3 days of "treatment" there is no change in the appearance of the green slime on either side of the shower.

6. What was the initial observation?
Green slime appearing on the bathtub!
2. Identify the:
Control Group
The side of the tub without coconut juice.
Independent (Manipulated) Variable
The application of coconut juice.
Dependent (Responding) Variable
The amount of green slime on the tub.

7. 3. What should Homer’s conclusion be
3. What should Homer’s conclusion be? Homer’s conclusion should be that coconut water will not reduce or get rid of the green slime that has developed on his tub.

8. Bart believes that mice exposed to radio waves will become extra strong (maybe he's been reading too much Radioactive Man). He decides to perform this experiment by placing 10 mice near a radio for 5 hours. He compared these 10 mice to another 10 mice that had not been exposed. His test consisted of a heavy block of wood that blocked the mouse food. He found that 8 out of 10 of the mice exposed to radio waves were able to push the block away. 7 out of 10 of the other mice were able to do the same.

9. Independent (Manipulated) Variable
Identify the:
Control Group
The mice NOT exposed to the radio waves is the control group, because they are given the “normal” conditions.
Independent (Manipulated) Variable
The independent variable (what you change) is the exposure to radio waves.
Dependent (Responding) Variable
The dependent variable (what you measure) is the strength of the mouse.

10. 2. What should Bart’s conclusion be?
According to his results, Bart can conclude that the radio waves might have impacted the strength of the mice, but not enough that there is a large difference between groups of mice!
3. How could Bart’s experiment be improved?
Ex. Mice could be given a different task, exposure to radio waves could be longer or over many days, etc.

11. Krusty was told that a certain itching powder was the newest and best thing on the market, it even claims to cause 50% longer lasting itches. Interested in this product, he buys the itching powder and compares it to his usual product. One test subject (A) is sprinkled with the original itching powder, and another test subject (B) was sprinkled with the experimental itching powder. Subject A reported having itches for 30 minutes. Subject B reported to have itches for 45 minutes.

12. Independent (Manipulated) Variable
Identify the:
Control Group
Subject A, who was given the original itching powder.
Independent (Manipulated) Variable
The best and newest itching powder.
Dependent (Responding) Variable
The length of time subjects felt itchy for.

13. 3. Explain whether the data supports the advertisement’s claims about its product?
The difference in length of time (15 minutes) is long enough to warrant the conclusion that the new itching powder works better and causes 50% longer-lasting itches!

14. Lisa is working on a science project
Lisa is working on a science project. Her task is to answer the question: "Does Rogooti (which is a commercial hair product) affect the speed of hair growth". Her family is willing to volunteer for the experiment. Describe how Lisa could conduct her experiment to answer the question.

15. Lisa could start by measuring each family member’s hair growth speed over the course of one or two months, without the hair growth formula (commercial hair product). This would be considered the control group. Then, she could provide each of her family members with different measured amounts of the hair growth formula and measure the length of each person’s hair every week to see if it affects their normal rates of hair growth.