Complex sentence: Sometimes, independent variables may be included for other reasons, such as for their potential confounding effect, without a wish to test their effect directly., a function is typically graphed with the horizontal axis representing the independent variable and the vertical axis representing the dependent variable.
Split into simpler sentences: Sometimes, independent variables may be included for other reasons, such as for their potential confounding effect, without a wish to test their effect directly. A way to remember this is "Why depend on Y?", a function is typically graphed with the horizontal axis representing the independent variable and the vertical axis representing the dependent variable.