The aim of this NATO ASI has been to present an up-to-date overview of current areas of interest in amorphous materials, with particular emphasis on electronic properties and device applications. In order to limit the material to a manageable amount, the meeting was concerned almost exclusively with semiconducting materials. This volume should be regarded as a follow-on to the NATO ASI held in Sozopol, Bulgaria in 1996 and published as "Amorphous Insulators and Semiconductors" edited by M.F. Thorpe and M.1. Mitkova (Kluwer Academic Publishers, NATO ASI series, 3 High Technology – Vol. 23). The lectures and seminars fill the gap between graduate courses and research seminars. The lecturers and seminar speakers were chosen as experts in their respective areas, and the lectures and seminars that were given are presented in this volume. During the first week of the meeting, an emphasis was placed on introductory lectures while the second week focused more on research seminars. There were two very good poster sessions that generated a lot of discussion, but these are not reproduced in this volume as the editors wanted to have only larger contributions to make the proceedings more coherent.