Experimental Design Concepts

The video tutorial explains the differences between independent variables, dependent variables, constants, and controls in scientific experiments. It uses a practical example of a lawn experiment with different fertilizers to illustrate these concepts. The independent variable is the type of fertilizer used, while the dependent variable is the greenness of the grass. The control is a lawn with no fertilizer, and constants include factors like water and sunlight. The tutorial emphasizes the importance of changing only one independent variable to accurately determine its effect.

What is the main goal of the experiment involving the houses on the culdesac?

• To measure the amount of water each lawn needs

• To see which house gets the most sunlight

• To find out which fertilizer makes the grass greenest

• To determine which house has the largest lawn

In the context of the experiment, what is the independent variable?

• Type of grass

• Amount of sunlight

• Type of fertilizer

• Amount of water used

Why is it important to change only one variable in an experiment?

• To save time

• To ensure accurate results

• To make the experiment more complex

• To use less resources

What is measured as the dependent variable in this experiment?

• Greenness of the grass

• Amount of fertilizer used

• Type of grass

• Number of houses

How long do the participants wait before measuring the greenness of the grass?

• One week

• Four weeks

• Two weeks

• Three weeks

What is the purpose of having a control in an experiment?

• To increase the number of variables

• To reduce the cost of the experiment

• To provide a standard for comparison

• To make the experiment more interesting

In the experiment, what serves as the control?

• A house with no fertilizer

• A house with no grass

• A house with no sunlight

• A house with no water

What is a constant in the context of this experiment?

• A type of fertilizer

• A variable that changes

• A factor that remains the same

• A measurement taken at the end

Which of the following is an example of a constant in the experiment?

• Type of fertilizer

• Number of houses

• Greenness of the grass

• Amount of sunlight

Why is it important to have constants in an experiment?

• To make the experiment more challenging

• To ensure that the results are due to the independent variable

• To increase the number of measurements

• To reduce the number of variables