1. Building the Semantic Web
“Better things for Better Living
Through Metadata”
Frank Manola •
***March 2002 review
***SW_Mar02reviewv2
This is a review of progress since the September 2001 review.
MITRE Sponsored Research
© 2001, The MITRE Corporation

2. Problem
The World Wide Web was originally aimed at providing information to people, not other software
Web resources don’t have descriptions of their meanings or capabilities that programs can understand
These meanings often involve talking about non-Web things (e.g., people)
Result: software can’t provide relevant information or services with precision, reflecting user intent and needs

3. “Semantic” = “Esoteric AI”?
“Semantic Web my behind! I just want to order a pizza, not have mozarella explained to me.”
Many Semantic Web applications can be rather straightforward, e.g.:
Simple content metadata (provenance, ratings)
Privacy policies
Subject-based catalogs
Site maps
Digitally-signed metadata
Description-based service brokering
Here, “Semantic Web applications” means “applications of more machine-interpretable data on the Web (or, in fact, anywhere else)
There is quite a lot of simple content metadata on the Web already, in various forms (including RDF). One of the goals is to provide a unified framework or model for this metadata, so that it can be interpreted by generalized processors, even if the representations are different (RDF, HTML META elements, etc.)

4. What is the Semantic Web?
The Semantic Web is about making the Web machine-processable
It’s important for the machines to have the semantics, but it doesn’t matter how the machines acquire the semantics
The Semantic Web is an evolution of the Web
Universal connectivity is an important aspect of the problem, and the solution
It won’t happen everywhere, all at once
Don’t discount the effects of thousands of smart non-researchers working on it
In addition to “supports matching resources to requests”, this helps with any “knowledge processing” activities (e.g., agent communications of all kinds)

5. RDF in the Semantic Web Unicode URIs
Tagged data: XML + Namespaces + XML Schema
Resource Description Framework
+ RDF Schema
Ontology support (OWL)
Logic
Proof
Trust
Digital Signatures KR
Rules
Data
Meta-
data
Semantic Web Architecture
(Tim Berners-Lee, W3C)
Struc-
tured
docs.
This is TBL’s “layer cake” picture (slightly clarified). The point is that RDF provides the key “data model” on which the higher levels are based.

6. RDF Statement Model http://www.foobar.org/index.html
“The creator of page is
subject
predicate
object
Notes about this example:
* unambiguously identifies a person (here, based on his employee number)
* is an unambiguous reference to the “creator” attribute in the Dublin Core metadata attribute set
* Use of Web identifiers allows us to begin to develop and use a shared vocabulary on the Web, reflecting (and creating) a shared understanding of the concepts we talk about
* “Anyone can say anything about anything” means no restriction to a single way of categorizing or relating things
* you can refer to anything you want, and add your own relationships
* You need not “own” something to add information about it
Ntriple:

7. Getting Involved “you can’t beat something with nothing”
Be in the right places
“the Internet is based on rough consensus and running code”
Show stuff people can use (in places they can use it)