This is a collection of pedagogical lectures and research papers that were presented during a combined course/conference program held at the International Centre for Theoretical Physics in Trieste in the summer of 1991. The lectures begin from an elementary level and were intended to bring student participants to the point where they could appreciate the research conference that came at the end of program.
From path integrals to anyons, G.S. Canright; solution of the problem with the Peynman variational principle for path integrals in the presence of a magnetic field, J.T. Devreese and F. Brossens; evaluating the path integral - field theory estimates via stochastic quantization, C.R. Doering; path integrals for open quantum systems - general theory and dynamical simulation, R. Egger et al; Poisson path integrals for certain field theories, B. Gaveau; path integral approach to interaction and tunnelling times, P. Hanggi; path integrals in phase space, M.S. Marinov; on the ground state energy of the polaron, J. Poulter and V. Sayakanit; the question of the tunnelling time duration - some contributions to its determination, A. Ranfagni and D. Mugnai; selected topics in path integration, L.S. Schulman; tunnelling and the path decomposition expansion, P. van Baal; quantum propagators - Feynman's integral and Bohm's causal interpretation, F.W. Wiegel; and others.