This volume brings the reader up to date on transport phenomena, including electrical and thermal conductivity and infrared properties. In addition, electron tunneling and the characteristics and applications of films are discussed; the preparation of the necessary samples has proceeded, and a sizeable body of reproducible data has become available. Pressure effects are also presented; considerable progress has been made in relating them to the crystallographic and electronic structure of high temperature superconductors. The preparation and characterization of bulk samples is also