Question

question 5: experimental design challenge
a student wants to test whether different types of music affect plant growth. they set up the following experiment:

• 3 plants listening to classical music (in a sunny window)
• 3 plants listening to rock music (in a shaded area)
• 3 plants with no music (in a sunny window)

a) what is wrong with this experimental design?
b) how would you improve this experiment to make it more reliable?
part 4: real - world application
question 6: everyday science
think about a question you have about the world around you that could be answered through experimentation.
a) write your research question:
b) identify the variables:

• independent variable:
• dependent variable:

c) describe how you would conduct this experiment:

Explanation:

Question 5a:

The experimental design has multiple variables. The plants listening to classical music and rock - music are in different light conditions (sunny vs shaded), so it's impossible to determine if any differences in plant growth are due to the music or the light.

Question 5b:

To improve the experiment, keep all non - music related factors constant. Place all plants in the same light conditions (either all sunny or all shaded), use the same type and size of plants, same soil, same watering schedule etc.

Question 6a:

An example research question could be: Does the amount of caffeine in water affect the growth rate of bean plants?

Question 6b:

• Independent variable: Amount of caffeine in water
• Dependent variable: Growth rate of bean plants

Question 6c:

Select a number of identical bean plants. Prepare different solutions with varying amounts of caffeine (e.g., 0mg, 50mg, 100mg per liter of water). Water each plant with its respective solution at a regular schedule. Measure the height of the plants every few days over a set period of time and record the data.

Answer:

Question 5a:

There are multiple variables (music type and light conditions), making it impossible to isolate the effect of music on plant growth.

Question 5b:

Keep all non - music factors (light, plant type, soil, watering etc.) constant.

Question 6a:

Does the amount of caffeine in water affect the growth rate of bean plants?

Question 6b:

• Independent variable: Amount of caffeine in water
• Dependent variable: Growth rate of bean plants

Question 6c:

Select identical bean plants. Prepare different caffeine - water solutions. Water plants regularly with respective solutions. Measure plant height over time and record data.