In previous works, we have presented two methodologies to obtain fuzzy rules in order to describe the behaviour of a system. We have used Artificial Neural Netorks (ANN) with the {\it Backpropagation} algorithm, and a set of examples of the system. In this work, some modifications which allow to improve the results, by means of an aptation or refinement of the variable labels in each rule, or the extraction of local rules using distributed ANN, are showed. An interesting application on the assignement of semantic to the classes obtained in a classification without previous classes process is also included.