@INPROCEEDINGS{ECAI06,
  AUTHOR = {Piero Bonatti and 
               Daniel Olmedilla and
               Joachim Peer},
  TITLE = {Advanced Policy Explanations},
  BOOKTITLE = {17th European Conference on Artificial Intelligence (ECAI 2006)},
  MONTH = {Aug-Sep},
  YEAR = 2006,
  ADDRESS = {Riva del Garda, Italy},
  PUBLISHER = {IOS Press},
  PAGES = {200-204},
  KIND = {conference},
  URL = {2006/2006_ECAI_explanations.pdf},
  ABSTRACT = {The frameworks for protecting security and privacy can be effective only if
  common users---with no training in computer science or logic---increase
  their awareness and control over the policy applied by the systems they
  interact with.  Towards this end, we introduce a mechanism for answering
  \emph{why, why-not, how-to}, and \emph{what-if} queries on rule-based
  policies for trust negotiation.  Our framework is \emph{lightweight} and
  \emph{scalable} but it fulfills the main goals of modern explanation
  facilities.  We adopt a novel \emph{tabled explanation structure}, that
  simultaneously shows local and global (intra-proof and inter-proof)
  information, thereby facilitating navigation.  To focus answers in the trust
  negotiation domain, we introduce suitable heuristics for removing the
  irrelevant parts of the derivations.}
}