What are degrees of freedom?
"the number of variables that can be varied independently"
I'm sorry, but this means nothing to me. Which variables are those? So, I'm getting a sample of 36 elements and I want the standard deviation, so the degress of freedom are 36 minus one. Why 35 of these elements can be varied freely and one not? And if I take two samples for a regression, it's two elements that cannot be varied freely! Can someone gimme a clue about all that degrees of freedom thing?