I have a question concerning statistical conventions. I want to report the classification rate of a 3-fold cross validated machine learning experiment. Of course I report the mean and some measure of the diversity in the different folds. I want to use a shorthand notation like $95.5\% \pm 0.9\%$.
My question is: What is most commonly used as "measure of the diversity"? On Wikipedia we find that standard deviation or standard error is used. On the same page under In statistics we find that usually it is corresponding to either 1 or 2 standard deviation.
So is there a best practice what to report? Standard deviation, standard error or even variance? And 1 or 2 times?