While expert systems technology originated in the United States, its
development has become an international concern. Since the start of the
DENDRAL project at Stanford University over 15 years ago, with its
objective of problem-solving via the automation of actual human expert
knowledge, significant expert systems projects have been completed in
countries rang- ing from Japan to France, Spain to China. This book
presents a sample of five such projects, along with four substantial
reports of mature studies from North American researchers. Two important
issues of expert system design permeate the papers in this volume. The
first concerns the incorporation of substantial numeric knowledge into a
system. This has become a significant focus of work as researchers have
sought to apply expert systems tech- nology to complex, real-world
domains already subject to statistical or algebraic description (and
handled well at some level in numeric terms). A second prominent issue
is that of representing control knowledge in a manner which is both
explicit, and thus available for inspection, and compatible with the
semantics of the problem domain.