Abstract Distributed servi es in a ontext-aware Web servi e system or in a servi e omposition need to ouple ontext information from dierent

sour es in order to be able to interpret ontext information. Su h interpreta-

tion is a prerequisite before servi es an adapt themselves to be ontext-aware.

However, ontext oupling in ontext-aware Web servi e systems is a omplex

issue. It is related not only to how we represent and transfer ontext infor-

mation among Web servi es, but also to how we support the ontext storage,

and how we ensure se urity and priva y issues of ontext information. Con-

text oupling te hniques for Web servi e systems will be dierent from that

of tightly oupled systems be ause, with Web servi e systems, ontext in-

formation is typi ally shared a ross the boundaries of organizations that host

Web servi es. This hapter aims at presenting an overview of ontext oupling

te hniques, their related issues, and their impli ation for a ontext-aware Web

servi e system. Our approa h is to study existing te hniques implemented in

urrent systems, to present open ontext oupling issues in urrent and future

ontext-aware Web servi e systems, and to suggest further resear h dire -