This volume contains the Proceedings of the 9th Italian Workshop on Neural Nets WIRN VIETRI-97, organised by the International Institute for Advanced Scientific Studies ((Eduardo R. Caianiello" (IIASS), the Societa Italiana Reti Neuroniche (SIREN) and the IEEE NNC Italian RIG. As in the previous editions some invited and reviewed talks on updated subjects are presented in addition to the original contributions selected by the Refereeing Committee. Also included is Professor C.M. Bishop's Invited paper on: * Latent Variables, Topographic Mappings and Data Visualization; and two review talks that deal with updated topics: * Fuzzy Neural Networks for Pattern Recognition; * A Unifying View of Gradient Calculations and Learning for Locally Recurrent Neural Networks; For publication the original contributions have been assembled into 4 sections: Applications, Architectures and Algorithms, Mathematical Models, Pattern Recognition and Robotics. The Editors thank the invited speaker and all the participants for having contributed to the success of the Workshop by submitting high quality manuscripts, and also express gratitude to the Refereeing Committee for the high quality of the selection process. Maria Marinaro Roberto Tagliaferri VI Organizing -Scientific Committee: B. Apolloni (Univ. Milano), A. Bertoni (Univ. Milano), D.O. Caviglia (Univ. Genova), P. Campadelli (Univ. Milano), A. Colla (ELSAG BAILEY -Genova), M. Frixione (1IASS), C. Furlanello (IRST -Trento), A. Esposito (1IASS), G.M. Guazzo (1IASS), M. Gori (Univ. Firenze), F. Lauria (Univ. Napoli), M. Marinaro (Univ. Salerno - IIASS), F.