The Scientific Method:
  • State the problem
  • Gathering Information
  • Form a hypothesis
  • Test the Hypothesis with an Experiment
  • Analyzing the Data
  • Drawing Conclusion

Scientific Method/Cats

Read the story and don't write the blue text:

A pet owner had his four cats boarded while he travels. The cats seemed healthy when they arrived, but a technician notices that two of the cats start scratching and chewing at their skin. After three days, these same two cats have bare patches of skin with red sores. The technician knows that cat's sometimes change their behavior when moved to a new place, so she watches all four cats for two days. Other than the scratching and chewing by the cats with sores, the behavior of all four cats seems the same. The technician called the owner and found out that he fed the cats the same food as she did.

While observing the cats, the technician also noticed that the cats scratched most after using the litter box. She called the owner and asked what brand of litter he put in the cat's litter box. The owner used a different brand than she did, so she compared the ingredients of the two kinds of litter. The difference was that the owners litter was deodorant free, while the brand she used had a deodorant. Based on this information the technician formed a hypothesis.

The technician got the cats owner’s permission to test her hypothesis. One cat was used as a control and the other cat experienced the manipulated variable. The technician observes the cats for one week. During this time she collects data. The data show that the control cat scratches and chews more often than the experimental cat does. The sores on the skin of the experimental cat begin to heal, but those on the control cat do not. The technician then switched the litter of the control and experimental cat to test her findings.

The technician knows that cat's sometimes change their behavior when moved to a new place, so she watches all four cats for two days. Other than the scratching and chewing by the cats with sores, the behavior of all four cats seems the same. The technician called the owner and found out that he fed the cats the same food as she did.

While observing the cats, the technician also noticed that the cats scratched most after using the litter box. She called the owner and asked what brand of litter he put in the cat's litter box. The owner used a different brand than she did, so she compared the ingredients of the two kinds of litter. The difference was that the owners litter was deodorant free, while the brand she used had a deodorant.


The technician gets the cats owners permission to test her hypothesis. The cat using litter with deoderant would be the control used for comparison. The cat just being given deoderant-free litter would be the experimented on subject. The technician observes the cats for one week. During this time she collects data. The data show that the control cat scratches and chews more often than the experimental cat does. The sores on the skin of the experimental cat begin to heal, but those on the control cat do not.

Take Cornell Style notes on the following using Science Notebook pages 13 & 14.
Key Terms:
A hypothesis is an explanation that can be tested.
An experiment tests a hypothesis.
A control is the standard to which the outcome of a test is compared.
A manipulated variable is something in an experiment that the experimenter changes. (An experiment should have only one)
A responding variable is something in an experiment that changes because of the manipulated variable.
A conclusion is a statement explaining if the evidence from the experiment supports the hypothesis or not.

Use the information in the reading to complete the 10 statements below or answer the questions.
What is the problem?
1. The problem is…

What three pieces of information were gathered?
2. Information was gather on ……, ……, and …….

What hypothesis should the technician form?
3. The ……in the litter is causing….

How would you test the hypothesis?
4. One cat would be left using litter containing deodorant, while the other cat would be given….

What “control” could you include in this testing of the hypothesis?
5. A control for this experiment would be the cat ….

What is the manipulated variable in this test?
6. The manipulated variable is….

What is the responding variable in this test?
7. The responding variable is…

What data should be collected in this test?
8. The data that should be collected is….

What conclusion can be drawn from this data?
9. The deodorant appears to be…

How could the technician be double sure of her conclusion?
10. The litter of the control cat.....

Bonus (not required)
How could the technician be triple sure of her conclusion?