Research Topic: The Semantic Web - Reference Page for Higher Education

This web page focuses on the impact Semantic Web technology might have on the field of education. The guiding question is simple: “What is the Semantic Web, and should institutions of higher education, particularly schools of education and educational research, be interested in it?” The technology has attracted significant research and investment dollars for industry, but little is occurring in the educational community, except in Europe, parts of Asia, and Canada. The intent of this page is to introduce the technology concepts, ask questions, create dialog, and spur interest that will lead to collaborative ventures.

As educators, we need to ask:

What is the Semantic Web?
Why is it that the Semantic Web is being designed for non-human content consumers, such as “… services, applications, bots and other automated components…” (Kobielus, 2007)?
Why is the Dewey Decimal System not going to serve us in the information age?
Who (or what businesses) are involved with developing the Semantic Web?
If Eli Lilly scientists use Semantic Web technologies to build a complete picture of the most likely drug targets for a given disease (very complex), then why can’t we use a similar approach to identify suitable learning/training solutions personalized for an individual’s particular needs?
In the field of education, who is doing what with research into the Semantic Web?

What is the Semantic Web?

The vision of the Semantic Web is that it will become increasingly a Services Oriented Architecture (SOA) (Kobielus, 2007). Where the first phase of the Web (i.e., Web 1.0, if you will) saw a technology that permits content to be available everywhere that is readable, searchable, and understandable by human consumers, the second phase (i.e., Web 2.0) improved on the first by expanding the range of media forms that can be published to the Web: we saw the introduction of blogs, wikis, podcasting, and mashups (Kobielus, 2007). The Web in this second phase also saw the development of social networking technologies, such as Facebook, MySpace, and social web page tagging Del.icio.us. The anticipated next phase, (i.e., Web 3.0, again, the version number reflects no official recognition of technical state, but rather it is used as a differentiator for the sake of convenience) will see an increase in non-human content consumers, such as “… services, applications, bots and other automated components…” (Kobielus, 2007, p. 30). Here follows a resource for more general information on the Semantic Web: http://semanticweb.org/?open.

ONTOLOGY

“In computer science and artificial intelligence, ontology languages are formal languages used to construct ontologies. They allow the encoding of knowledge about specific domains and often include reasoning rules that support the processing of that knowledge. Ontology languages are usually declarative languages, are almost always generalizations of frame languages, and are commonly based on either first-order logic or on description logic“ (http://en.wikipedia.org/wiki/Ontology_language).

“A body of formally represented knowledge is based on a conceptualization: the objects, concepts, and other entities that are assumed to exist in some area of interest and the relationships that hold among them (Genesereth & Nilsson, 1987) . A conceptualization is an abstract, simplified view of the world that we wish to represent for some purpose. Every knowledge base, knowledge-based system, or knowledge-level agent is committed to some conceptualization, explicitly or implicitly.

An ontology is an explicit specification of a conceptualization” (Gruber, T., http://ksl-web.stanford.edu/kst/what-is-an-ontology.html).

URL vs URI (i.e., Uniform Resource Locator vs Uniform Resource Identifier)

“The Web is an information space. Human beings have a lot of mental machinery for manipulating, imagining, and finding their way in spaces. URIs are the points in that space. Unlike web data formats, where HTML is an important one, but not the only one, and web protocols, where HTTP has a similar status, there is only one Web naming/addressing technology: URIs” (http://www.w3.org/Addressing/).

“In computing, a Uniform Resource Locator (URL) is a Uniform Resource Identifier (URI) which also specifies where the identified resource is available and the protocol for retrieving it.[1] In popular usage and in many technical documents it is often confused as a synonym for uniform resource identifier” (http://en.wikipedia.org/wiki/Uniform_Resource_Locator ). Two examples of URL are http://www.google.com or http://www.yahoo.com. Other examples with different access protocols are: https://www.wellsfargo.com/, ftp://ftp.gimp.org/, or mailto:gbradfor@mail.ucf.edu.

“… a Uniform Resource Identifier (URI) is a compact string of characters used to identify or name a resource on the Internet. The main purpose of this identification is to enable interaction with representations of the resource over a network, typically the World Wide Web, using specific protocols. URIs are defined in schemes defining a specific syntax and associated protocols” (http://en.wikipedia.org/wiki/Uniform_Resource_Identifier ). “A URL is a URI that, in addition to identifying a resource, provides means of acting.”

RDF (Resource Description Framework)

“The RDF data model is based upon the idea of making statements about Web resources in the form of subject-predicate-object expressions, called triples in RDF terminology. The subject denotes the resource, and the predicate denotes traits or aspects of the resource and expresses a relationship between the subject and the object. For example, one way to represent the notion "The sky has the color blue" in RDF is as the triple: a subject denoting "the sky", a predicate denoting "has the color", and an object denoting "blue". RDF is an abstract model with several serialization formats (i.e., file formats), and so the particular way in which a resource or triple is encoded varies from format to format" (http://en.wikipedia.org/wiki/Resource_Description_Framework).

Here follows an example statement expressed in RDF format:

<rdf:RDF

  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"

  xmlns:dc="http://purl.org/dc/elements/1.1/">

                    <rdf:Description rdf:about="http://en.wikipedia.org/wiki/Tony_Benn">

                                        <dc:title>Tony Benn</dc:title>

                                        <dc:publisher>Wikipedia</dc:publisher>

                    </rdf:Description>

</rdf:RDF>

To a human, the above could be read as “The title of this resource, which is published by Wikipedia, is 'Tony Benn.”

“The Resource Description Framework (RDF) integrates a variety of applications from library catalogs and world-wide directories to syndication and aggregation of news, software, and content to personal collections of music, photos, and events using XML as an interchange syntax. The RDF specifications provide a lightweight ontology system to support the exchange of knowledge on the Web” (http://www.w3.org/RDF/).

XML

* XML stands for EXtensible Markup Language

* XML is a markup language much like HTML

* XML was designed to carry data, not to display data

* XML tags are not predefined. You must define your own tags

* XML is designed to be self-descriptive

* XML is a W3C Recommendation

The Difference between XML and HTML is that XML is not a replacement for HTML. XML and HTML were designed with different goals: XML was designed to transport and store data, with focus on what data is. HTML was designed to display data, with focus on how data looks. HTML is about displaying information, while XML is about carrying information. XML Does not DO Anything. Maybe it is a little hard to understand, but XML does not DO anything. XML was created to structure, store, and transport information. The following example is a note to Tove from Jani, stored as XML:

<note>

<to>Tove</to>

<from>Jani</from>

<heading>Reminder</heading>

<body>Don't forget me this weekend!</body>

</note>

“The note above is quite self descriptive. It has sender and receiver information, it also has a heading and a message body. But still, this XML document does not DO anything. It is just pure information wrapped in tags. Someone must write a piece of software to send, receive or display it” (http://www.w3schools.com/xml/xml_whatis.asp).

OWL

“A. OWL is a Web Ontology language. Where earlier languages have been used to develop tools and ontologies for specific user communities (particularly in the sciences and in company-specific e-commerce applications), they were not defined to be compatible with the architecture of the World Wide Web in general, and the Semantic Web in particular” (http://www.w3.org/2004/OWL/).

DARPA Agent Markup Language (DAML)

“The World Wide Web (WWW) contains a large amount information which is expanding at a rapid rate. Most of that information is currently being represented using the Hypertext Markup Language (HTML), which is designed to allow web developers to display information in a way that is accessible to humans for viewing via web browsers. While HTML allows us to visualize the information on the web, it doesn't provide much capability to describe the information in ways that facilitate the use of software programs to find or interpret it. The World Wide Web Consortium (W3C) has developed the Extensible Markup Language (XML) which allows information to be more accurately described using tags. As an example, the word Algol on a web site might represent a computer language, a star or an oceanographic research ship. The use of XML to provide metadata markup, such as Algol, makes the meaning of the work unambiguous. However, XML has a limited capability to describe the relationships (schemas or ontologies) with respect to objects. The use of ontologies provides a very powerful way to describe objects and their relationships to other objects. The DAML language is being developed as an extension to XML and the Resource Description Framework (RDF). The latest release of the language (DAML+OIL) provides a rich set of constructs with which to create ontologies and to markup information so that it is machine readable and understandable” (http://www.daml.org/about.html). Additional resources: http://www.daml.org/.

SOA

Service Oriented Architecture (SOA) is “…an architectural style whose goal is to achieve loose coupling among interacting software agents. A service is a unit of work done by a service provider to achieve desired end results for a service consumer. Both provider and consumer are roles played by software agents on behalf of their owners.” “SOA is actually everywhere. Let's look at an example of SOA which is likely to be found in your living room. Take a CD for instance. If you want to play it, you put your CD into a CD player and the player plays it for you. The CD player offers a CD playing service, which is nice because you can replace one CD player with another. You can play the same CD on a portable player or on your expensive stereo. They both offer the same CD playing service, but the quality of service is different” (http://webservices.xml.com/pub/a/ws/2003/09/30/soa.html).