OK, I'm ashamed to say that I've drawn a blank on this:frust:

In less than 1,000 words distinguish the difference between an independant and dependant research variable.

It's probably so simple that it becomes one of those "forest and trees" issues:tunnel:

from Independent variable

"the independent variable is the variable that is manipulated to determine its relationship to the dependent variable"

y = mx+b.

x can be anything it wants, so independent

y is a function of whatever x is, so is dependent

Version 3 of the same song.

Independent-manipulated/controlled variable. This is what you vary, measure, etc. How much fertilizer/water/light added to the plant.

Dependent-variable of interest/under study. How tall the plant grows.

This assumes you're just interested in the descriptor of the variables (above), and not their relationship (whether two variables are independent/dependant).