Define "independent variable" and give an example of it in a research project.?

Answer 1

http://en.wikipedia.org/wiki/Independent_variable

It's the cause of an effect.
e.g. What are the causes for poverty? Possible independent variable 'lack of education'.

Answer 2

Without googling and drawing from memory: A variable is a symbol for which is expected a quantity of something changing over time, a constant is a symbol for something not expected to change over a time. A control variable is a symbol for something of a quantitive or measurable nature that is in the control of the experimenter (the experimenter controls the quantity for a control variable), the independent variable is a symbol for the theoretically connected co-efficient for the control variable, it is studied as the control variable is adjusted. Per control variable change or adjustment, an independent variable change is recorded. At each change for the control variable the change or no change is measured and recorded. In some experiments there are more than one control variable and more than one independent variable.

e.g. critical neuclear action differentials in respect to aggregate mass for a sample of uranium 238. For every mass of U238 added to a pile a measure for the neutron output is measured. U238 pile mass is the control variable, the neutron output is the independent variable.