Recently I've discovered the cutoff node (E. Miner 5.3 ), but i couldn't use it. My problem is that I can´t link it to another node...Could you help me with a reference about this node (i used F1 but it didn't help me)?
You should be able to add a Cutoff node to your diagram where a modeling node used to classify a binary target appears as a predecessor node in the process flow. The on line help describes usage with this overview
The node provides tabular and graphical information to assist users in determining appropriate probability cutoff point(s) for decision making with binary target models. The establishment of a cutoff decision point entails the risk of generating false positives and false negatives, but an appropriate use of the Cutoff node can help minimize those risks.
You will typically run the node at least twice. In the first run, you obtain all the plots and tables. In a subsequent runs, you can change the values of the Cutoff Method and Cutoff User Input properties, customizing the plots, until an optimal cutoff value is obtained.