What does dependant variable mean?

Answer 1

See link for the Wikipedia article. The dependent variable is sometimes called response variable, or outcome variable. During what year of school, K thru 12, do kids experience the greatest average change in height (or weight)? You are "manipulating" what year of school a child is in. You aren't making any changes on this-- this is just your independent variable. You are going to measure height change for each child, so a starting and ending measure is needed. Height is the dependent variable.

Answer 2

A dependent variable is what you measure in the experiment and what is affected during the experiment. The dependent variable responds to the independent variable. It is called dependent because it "depends" on the independent variable. In a scientific experiment, you cannot have a dependent variable without an independent variable.

Example: You are interested in how stress affects heart rate in humans. Your independent variable would be the stress and the dependent variable would be the heart rate. You can directly manipulate stress levels in your human subjects and measure how those stress levels change heart rate.

Answer 3

The dependent variable is the one you are interested in. It's the one you are looking at, to see if it changes.

For example:

If I want to see if water evaporates faster when it is hotter, I am changing the independent variable, temperature, and hoping to see a difference in the dependent variable, the rate of water evaporation.

I would be keeping the controlled variable of water volume the same between each repeat of the experiment, because that could inadvertently change the dependent variable, which I don't want.