What is the difference between the independent variable, dependent variable, experimental group, control group, constants

Answer 1

Independent Variable (as seen by the word independent) means that it is unaffected by any other variables in the experiment. This is normally the variable that is being manipulated or changed by the researchers. This is normally plotted on the x axis.

The dependent variable is the one which is being observed usually to see what effects the independent variable has on it. This is normally plotted on the y axis.

For example if researchers are trying to determine the effect of time on the ripening of bananas, Time would be the independent variable while the degree of ripeness is dependent.

Let’s say we want to switch this experiment up a little bit and see how bananas ripen under normal conditions versus how they ripen when a mutation is introduced in the bananas. The control group would be the normal bananas as they tell us the usual mode through which bananas ripen. On the other hand the experimental group is the bananas with mutations because they are the group we are studying. Some constants that would be needed would be the location or the climate in which the two groups of bananas are kept so that only the mutation affects the ripening of the bananas and not any other variables that aren’t “controlled” for.

Answer 2

In an experiment, the independent variable is the variable that you are testing the effect of, the one that you are actively manipulating (changing) to see what its effect(s) are.

Dependent variable is the variable you are monitoring the effect on.

Constant are the factors you are keeping the same so as not to muddy the focus of the experiment which is looking at the effect of fertilizer amount on tomato production.

Example: Experiment to test the effect of fertilizer amount of tomato production.

Experiment: Set up three tomato seedlings in three plants. Feed plant A 0cups fertilizer, plant B 1 cup fertilizer, Plant B 2 cup fertilizer. Count number of tomatoes produced by each plant in 5 month period.

Independent variable here is: Amount of Fertilizer.

Dependent variable: Number of tomatoes (tomato production)

Constant: All three plants need to be the same type, the same size, watered the same, kept in the same light conditions, everything that is kept the same.

Control group: Plant A with no fertilizer, we can compare results to this

Experiment group: Plant A and Plant B that had different amounts of fertilizer