Spongebob Controls Variables by Lisa Belton - Issuu - Free Printable

Problem Analysis and Solution

The worksheet focuses on understanding the scientific method, specifically controls and variables. Let's break down each part of the worksheet and solve the problems step by step.

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#### Part 1: Definitions
1. Control: A standard or baseline condition in an experiment that is not exposed to the manipulated variable. It serves as a reference point to compare the effects of the manipulated variable.
2. Variable: Any factor that can change or vary in an experiment. Variables are categorized into manipulated, responding, and controlled variables.
3. Manipulated Variable: The factor that the experimenter intentionally changes or manipulates to observe its effect on the responding variable.
4. Responding Variable: The factor that is measured or observed to see how it responds to changes in the manipulated variable.

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#### Part 2: Krusty Krabs Breath Mints

##### Experiment Description:
- Mr. Krabs created a secret ingredient for a breath mint to "cure" bad breath from eating crabby patties.
- He tested the breath mints on 100 customers with a history of bad breath.
- Group A (50 customers): Received the special breath mint with the secret ingredient.
- Group B (50 customers): Received a regular breath mint without the secret ingredient.
- Both groups were told they were getting the same breath mint.
- After two hours, 30 customers in Group A reported better breath, while 10 customers in Group B reported better breath.

##### Questions:

1. Which people are in the control group?
- Answer: Group B is the control group because they received the regular breath mint (no secret ingredient), serving as a baseline to compare the effects of the secret ingredient.

2. What is the manipulated variable?
- Answer: The manipulated variable is the presence or absence of the secret ingredient in the breath mint. Mr. Krabs changed this factor to observe its effect on bad breath.

3. What is the responding variable?
- Answer: The responding variable is the improvement in breath quality reported by the customers. This is what Mr. Krabs measured to determine the effectiveness of the secret ingredient.

4. What should Mr. Krabs' conclusion be?
- Answer: Mr. Krabs should conclude that the secret ingredient in the breath mint may have a positive effect on improving breath quality. This is because a higher percentage of customers in Group A (30 out of 50) reported better breath compared to Group B (10 out of 50).

5. Why do you think 10 people in group B reported fresher breath?
- Answer: The 10 people in Group B who reported fresher breath likely experienced a placebo effect. Even though they received a regular breath mint, their belief that they were getting a special breath mint improved their perception of their breath quality.

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#### Part 3: SpongeBob Clean Pants

##### Experiment Description:
- SpongeBob noticed his pants were dirty and wanted to test a new detergent called Clean-O.
- He washed one pair of pants in plain water and another pair in water with Clean-O detergent.
- After washing both pairs three times, the pants washed with Clean-O did not appear cleaner than those washed in plain water.

##### Questions:

6. What was the problem SpongeBob wanted to investigate?
- Answer: SpongeBob wanted to investigate whether the Clean-O detergent makes his pants cleaner than plain water.

7. What is the manipulated variable?
- Answer: The manipulated variable is the type of water used for washing the pants (plain water vs. water with Clean-O detergent).

8. What is the responding variable?
- Answer: The responding variable is the cleanliness of the pants after washing. SpongeBob measured this to determine the effectiveness of the Clean-O detergent.

9. What should SpongeBob's conclusion be?
- Answer: SpongeBob should conclude that the Clean-O detergent does not make his pants any cleaner than plain water. Since both pairs of pants appeared equally clean after washing, the detergent did not have a significant effect.

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Final Answers:

1. Control group: Group B
2. Manipulated variable: Presence or absence of the secret ingredient in the breath mint
3. Responding variable: Improvement in breath quality
4. Mr. Krabs' conclusion: The secret ingredient may improve breath quality.
5. Reason for Group B reporting fresher breath: Placebo effect
6. Problem SpongeBob investigated: Whether Clean-O detergent makes pants cleaner
7. Manipulated variable: Type of water used for washing (plain water vs. water with Clean-O)
8. Responding variable: Cleanliness of the pants
9. SpongeBob's conclusion: Clean-O detergent does not make pants any cleaner than plain water.

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Final Boxed Answers:

\[
\boxed{
\begin{array}{l}
1. \text{Group B} \\
2. \text{Presence or absence of the secret ingredient in the breath mint} \\
3. \text{Improvement in breath quality} \\
4. \text{The secret ingredient may improve breath quality.} \\
5. \text{Placebo effect} \\
6. \text{Whether Clean-O detergent makes pants cleaner} \\
7. \text{Type of water used for washing (plain water vs. water with Clean-O)} \\
8. \text{Cleanliness of the pants} \\
9. \text{Clean-O detergent does not make pants any cleaner than plain water.}
\end{array}
}
\]