A broad definition for the concept of
"semantics" as applied to the Semantic Web has been provided by Sheth et al.
(2005), in terms of three types of semantics:
- Implicit semantics. "This
type of semantics refers to the kind that is implicit in data and that is
not represented explicitly in any machine processable syntax."
- Formal semantics.
"Semantics that are represented in some well-formed syntactic form (governed
by syntax rules) is referred to as formal semantics."
- Powerful (soft)
semantics. "Usually, efforts related to formal semantics have involved
limiting expressiveness to allow for acceptable computational
characteristics. Since most KR mechanisms and the Relational Data Model are
based on set theory, the ability to represent and utilize knowledge that is
imprecise, uncertain, partially true, and approximate is lacking, at least
in the base/standard models. [...] Representing and utilizing these types of
more powerful knowledge is, in our opinion, critical to the success of the
Semantic Web. Soft computing has explored these types of powerful semantics.
We deem these powerful (soft) semantics as distinguished, albeit not
distinct from or orthogonal to formal and implicit semantics."
The three types of semantics are
included in the focus of MTSR'05.
A. et al.(2005). Semantics for the Semantic Web: The Implicit, the
Formal and the Powerful. Intl. Journal on Semantic Web and Information
Systems 1(1), 1-18.