SCIENTIFIC METHOD REVIEW: Identifying Variables Worksheet - ppt ... - Free Printable

Let's go through the Scientific Method Review: Identifying Variables Worksheet and analyze both experiments to ensure the variables are correctly identified. We’ll also explain the reasoning behind each answer.

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🔬 Experiment 1:

> *Different rose bushes are grown in a greenhouse for two months. The number of flowers on each bush is counted at the end of the experiment.*

#### ✔ Your Answers:
- IV (Independent Variable): DIFFERENT ROSE BUSHES
- DV (Dependent Variable): THE NUMBER OF FLOWERS THAT GROW

#### ✘ Issue with IV:
The independent variable should be the factor that is deliberately changed by the experimenter. In this case, if you're just growing different rose bushes (e.g., different varieties), then the type of rose bush is what's being varied — so your IV is correct, but let’s clarify it.

However, if these rose bushes are not being manipulated (like changing conditions), and they’re just naturally different types, then this might not be a controlled experiment unless the type of rose bush is the intentional variable being tested.

But assuming the goal is to test how different types of rose bushes produce flowers under the same conditions, then:

- IV: Type of rose bush (or variety) → ✔️ Correct
- DV: Number of flowers produced → ✔️ Correct
- CG (Control Group): Not specified or implied here — because there’s no group receiving standard treatment or baseline condition. All groups are different rose bushes. So, there is no control group unless one bush is considered "standard."

➡️ Conclusion:
- IV: Type of rose bush (your answer "different rose bushes" is acceptable, though more precise would be "type/variety of rose bush")
- DV: Number of flowers → ✔️ Correct
- CG: Not applicable or missing — since all plants are experimental groups. No control is defined.

👉 So, no control group is present in this experiment.

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🌻 Experiment 2:

> *You water three sunflower plants with salt water. Each plant receives a different concentration of salt solutions. A fourth plant receives pure water. After a two-week period, the height is measured.*

#### ✔ Your Answers:
- IV: THE AMOUNT OF SALT IN THE SOLUTION
- DV: THE HEIGHT OF THE SUNFLOWERS
- CG: THE PLANT THAT RECEIVED PURE WATER (NO SALT)

#### ✔️ Evaluation:
These answers are all correct!

Let’s break it down:

- IV (Independent Variable): The amount of salt in the solution (i.e., salt concentration) — this is what the experimenter changes intentionally.
- DV (Dependent Variable): The height of the sunflowers — this is what is measured as a result of the change in salt concentration.
- CG (Control Group): The plant that received pure water — this serves as a baseline to compare against the salt-treated plants. It helps determine whether salt affects growth.

✔ This is a well-designed experiment with clear variables.

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✔ Final Summary:

| Experiment | IV | DV | CG |
|----------|----|----|-----|
| 1 | Type of rose bush | Number of flowers | None (no control group) |
| 2 | Concentration of salt in water | Height of sunflowers | Plant watered with pure water |

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💡 Key Concepts Reminder:

- Independent Variable (IV): What you change.
- Dependent Variable (DV): What you measure.
- Control Group (CG): The group that does not receive the experimental treatment (baseline for comparison).

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✔ Conclusion:

Your answers are mostly correct! Just note that Experiment 1 lacks a control group, so CG should be listed as "None" or "Not applicable" unless otherwise specified.

Let me know if you'd like help revising the worksheet!