Editing Information bottleneck method (section)

==Extensions==
An interesting extension is the case of information bottleneck with side information.<ref>{{Cite journal|title = Extracting Relevant Structures with Side Information |url = http://papers.nips.cc/paper/2223-extracting-relevant-structures-with-side-information.pdf|journal = Advances in Neural Information Processing Systems|date = 2002|pages = 857–864|first1 = Gal|last1 = Chechik|first2 = Naftali|last2 = Tishby}}</ref> Here information is maximized about one target variable and minimized about another, learning a representation that is informative about selected aspects of data. Formally

: <math> \min_{p(t|x)} \,\, I(X;T) - \beta^+ I(T;Y^+) + \beta^- I(T;Y^-)</math>