
269Implementing an Inference Controller forSocial Media Data
until they are requested (Bray et al., 2000). XML is also equipped with features for writing rules
(Grosof and Poon, 2003; Governatori, 2005; Horrocks et al., 2004). In addition, RDF and OWL
can be represented in an XML syntax (Bechhofer et al., 2004; Horrocks et al., 2004). Our choice
of an XML language allows us to take as input any high-level policy specication and an associ-
ated parser that maps it to a low-level policy format. The high-level application user also benets
from our use of an XML language, since XML is an open standard that is widely used and many
data exchange ...