Question

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. 20. describe how lisa would perform this experiment. identify the control group, and the independent and dependent variables in your description.

Explanation:

1. Experimental Design:

• Participants: Recruit family members (volunteers). Split them into two groups (e.g., Group A - experimental, Group B - control) ensuring similar hair types, lengths, and health to control confounding variables.
• Procedure:
• Control Group (Group B): Do not apply Rogooti. Maintain regular hair care routine (e.g., same shampoo, brushing, diet).
• Experimental Group (Group A): Apply Rogooti as per product instructions (e.g., daily/weekly) while maintaining the same regular hair care routine as Group B.
• Duration: Conduct the experiment for a set period (e.g., 4 weeks). Measure hair growth (e.g., length in cm) at the start and end for all participants.
• Variables:
• Independent Variable: Application of Rogooti (Group A gets it, Group B doesn’t).
• Dependent Variable: Speed of hair growth (measured as change in hair length over time).
• Control Group: Group B (no Rogooti) to compare against Group A. Other factors (hair care routine, diet, etc.) are controlled to isolate Rogooti’s effect.

1. Data Collection & Analysis: Record hair length data. Calculate average hair growth for each group. Compare the two groups to see if Rogooti - treated group (A) has significantly different (faster/slower) growth than the control (B).

Answer:

Experimental Procedure:

1. Recruit & Group Volunteers: Recruit family members. Divide them into two groups (Experimental - A, Control - B) with similar hair characteristics (type, length, health) to minimize confounding factors.
2. Control Group (B) Protocol: Instruct Group B to follow their regular hair care routine (e.g., use their usual shampoo, brush hair, maintain diet) without applying Rogooti.
3. Experimental Group (A) Protocol: Instruct Group A to follow the same regular hair care routine as Group B, but also apply Rogooti according to the product’s instructions (e.g., daily/weekly application).
4. Duration & Measurement: Conduct the experiment for a fixed period (e.g., 4 weeks). At the start and end, measure each participant’s hair length (e.g., in centimeters) to calculate hair growth.

Variables & Groups:

• Control Group: Group B (no Rogooti application) — used to establish a baseline for hair growth without Rogooti.
• Independent Variable: Application of Rogooti (Group A receives it; Group B does not) — the factor being tested.
• Dependent Variable: Speed of hair growth (measured as the change in hair length over the experiment’s duration) — the outcome being measured.

Analysis:

After the experiment, calculate the average hair growth for Group A (Rogooti - treated) and Group B (control). Compare the two averages. If Group A’s average growth is significantly different (faster/slower) than Group B’s, it suggests Rogooti affects hair growth speed.