Question

open - ended questions

1. explain the difference between the independent and dependent variables in an experiment. give an example.
2. why is it important to have a control group when performing an experiment?

Explanation:

1. An independent variable is the variable that is manipulated or changed by the researcher in an experiment. The dependent variable is the variable that is measured and is expected to change as a result of the manipulation of the independent variable. For example, in an experiment testing the effect of different amounts of sunlight (independent variable) on plant growth (dependent variable), the amount of sunlight is changed by the researcher and the growth of the plants is then measured.
2. A control group is important in an experiment because it provides a baseline for comparison. It is a group that does not receive the experimental treatment. By comparing the results of the experimental group (the group that receives the treatment) to the control group, researchers can determine if the treatment has a real effect or if the results are due to chance or other factors.

Answer:

1. An independent variable is manipulated; a dependent variable is measured. Example: sunlight amount (independent) affecting plant growth (dependent).
2. It provides a baseline for comparison to determine treatment - effect validity.