Diane-Michel.com

Source: Semantic Web FAQ
Resource: W3C-Semantic Web
Retrieved: http://www.w3.org/2001/sw/SW-FAQ#What1

What is the Semantic Web activity at W3C?

The Semantic Web Activity at W3C groups together all the Working and Interest Groups whose goals are to improve the current Semantic Web technologies or to contribute to their wider adoption. The activity home page gives an up-to-date list of the current work at W3C.

How does the Semantic Web relate to Artificial Intelligence?

Some parts of the Semantic Web technologies are based on results of Artificial Intelligence research, like knowledge representation (e.g., for ontologies), model theory (e.g., for the precise semantics of RDF and RDF Schemas), or various types of logic (e.g., for rules). However, it must be noted that Artificial Intelligence has a number of research areas (e.g., image recognition) that are completely orthogonal to the Semantic Web.

It is also true that the development of the Semantic Web brought some new perspectives to the Artificial Intelligence community: the Web effect, i.e., the merge of knowledge coming from different sources, usage of URIs, the necessity to reason with incomplete data; etc.

How does the Semantic Web relate to Description Logic?

Description Logic is the mathematical theory (stemming from knowledge representation) that is at the basis of some of the technologies defined on the Semantic Web: OWL-DL and OWL-Lite.

How does the Semantic Web relate to XML? When should I use RDF and when should I use XML?

Both formalisms have their strengths and weaknesses; their area of usage is different. The two data models serve different constituencies and the choice really depends on the application. There is no better or worse; only different.

One of XML’s strengths is its ability to describe strict hierarchies. Applications may rely and indeed exploit the position of an element in a hierarchy: for example, most browsers provide a different rendering of HTML’s li element depending on how deep the enclosing list is. XML makes it easy to control the content via XML Schemas and combine XML data that abide to the same Schema or DTD.

However, combining different XML hierarchies (technically, DOM trees) within the same application may become very complex. XML is not an easy tool for data integration. On the other hand, RDF consists of a very loose set of relations (triples). Due to its usage of URIs it is very easy to seamlessly merge triple sets, ie, data described in RDF within the same application; it is therefore ideal for the integration of possibly heterogenous information on the Web. But this has its price: reconstructing hierarchies from RDF may become quite complex. As an example, it would be fairly complicated (and unnecessary) to describe, eg, vector graphics, using RDF; use SVG instead!

For existing XML-based vocabularies, one can develop an GRDDL transformation to RDF using a language such as XSLT and then use the power of RDF to merge your pre-existing XML formats. For new vocabularies, this technique allows you to use both XML and RDF-based versions of your vocabulary, gaining the advantages of both.

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References:

W3C Semantic Web (2001). W3C Semantic Web Frequently Asked Questions. Retrieved March 6, 2008, from http://www.w3.org/2001/sw/SW-FAQ#What1Copyright © 1994-2008 W3C ^® (MIT, ERCIM, Keio), All Rights Reserved. W3C liability, trademark, document use and software licensing rules apply.

Source: Semantic Web FAQ
Resource:   W3C-Semantic Web
Retrieved: http://www.w3.org/2001/sw/SW-FAQ#What1
 

What is the “killer application” for the Semantic Web?

It is difficult to predict what a “killer application” is for a specific technology, and the prediction is often erroneous. That said, the integration of currently unbound and independent “silos” of data in a coherent application is certainly a good candidate. Specific examples are currently explored in areas like Health Care and Life Sciences, Public Administration, Engineering, etc.

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Will I “see” the Semantic Web in my everyday browser?

Not necessarily, at least not directly. The Semantic Web technologies may act behind the scenes, resulting in a better user experience, rather than directly influencing the “look” on the browser. This is already happening: there are Web Sites (e.g., Sun’s white paper collection site, or Nokia’s support portal for their S60 series device, Oracle’s virtual press room, Harper’s online magazine) that use Semantic Web technologies in the background.

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Is the Semantic Web just research, or does it have industrial applications?

As all innovative technologies, the Semantic Web underwent an evolution starting at research labs, being then picked up by the Open Source community, then by small and specialized startups and finally by business in general. Remember: the Web was originally developed in a High Energy Physics center!

At present, the Semantic Web is increasingly used by small and large business. Oracle, IBM, Adobe, Software AG, or Northrop Grumman are only some of the large corporations that have picked up this technology already and are selling tools as well as complete business solutions. Large application areas, like the Health Care and Life Sciences, look at the data integration possibilities of the Semantic Web as one of the technologies that might offer significant help in solving their R&D problems.

It is worth consulting the list of Semantic Web Case Studies and Use Cases; it gives a good overview of existing applications. Note that the list is often updated, when new application examples come in.

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Does one have to understand the theory of formal ontologies and logic to use the Semantic Web?

First of all, as pointed out elsewhere in this document, one can develop Semantic Web applications without using ontologies. Very useful applications can be built without those, relying on the most fundamental, and simple concept of the Semantic Web. However, even if ontologies, rules, reasoners, etc, are used, the average user should not care about the complexities of, say, the details of reasoning. All this is done “under the hood”. What the developer needs to operate with are usually simple logical patterns of the sort “Given that (Flipper  isA  Dolphin) and (Dolphin  isAlso  Mammal), one can conclude that (Flipper  isA  Mammal)“.

Compare it to SQL. The official SQL standards, the formal semantics of SQL, and indeed its implementations are extremely complex and understood by a few specialists only. Nevertheless, a large number of users use SQL in practice, without caring about the underlying complexities.

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How is the Semantic Web related to the existing Web?

The Semantic Web is an extension of the current Web and not its replacement. Islands of RDF and possibly related ontologies can be developed incrementally. Major application areas (like Health Care and Life Sciences) may choose to “locally” adopt Semantic Web technologies, and this can then spread over the Web in general. In other words, one should not think in terms of “rebuilding” the Web.

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References:

W3C Semantic Web (2001). W3C Semantic Web Frequently Asked Questions. Retrieved March 6, 2008,  from  http://www.w3.org/2001/sw/SW-FAQ#What1

Copyright © 1994-2008 W3C ^® (MIT, ERCIM, Keio), All Rights Reserved. W3C liability, trademark, document use and software licensing rules apply.

I’ve decided it is now time to focus on trying to decipher and understand the Semantic Web in more detail.   I’ve already covered online learning environments, collective intelligence, and collaborative platforms.   Now I’m ready to go on to the holy grail so to speak.   It is necessary for me to truly understand the Semantic Web, and how it can be practically applied for collective intelligence, and facilitating breakthrough medical research.

So as I go about the learning process I will be sharing my stages of discovery in progressive postings.   The best way to learn is to try and teach others right?
As I mentioned in a previous posting: Semantics according to Merriam-Webster (1986) originates from the Greek word semantikos.   Semantics literally means:   “significant, to signify, mean, or relating meaning in language. It is the study of meanings.”  

The first obvious choice for the best information on the Semantic Web  is the W3C itself.   In the beginning I’ll run just the facts first, then we’ll break it down into an understandable  course section by section.  

If you prefer attached you will find a Word document with bullet points to help you remember the material.

Diane Michel – Semantic Web Bullet Points

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Source: Semantic Web FAQ
Resource:   W3C-Semantic Web
Retrieved: http://www.w3.org/2001/sw/SW-FAQ#What1

The Semantic Web provides a common framework that allows data to be shared and reused across application, enterprise, and community boundaries. It is a collaborative effort led by W3C with participation from a large number of researchers and industrial partners.

How would you define the main goals of the Semantic Web?

The vision of the Semantic Web is to extend principles of the Web from documents to data. This extension will allow to fulfill more of the Web’s potential, in that it will allow data to be shared effectively by wider communities, and to be processed automatically by tools as well as manually.

The Semantic Web allows two things.

1.  It allows data to be surfaced in the form of real data, so that a program doesn’t have to strip the formatting and pictures and ads off a Web page and guess where the data on it is.

2.  It allows people to write (or generate) files which explain €”to a machine €”the relationship between different sets of data. For example, one is able to make a “semantic link ” between a database with a “zip-code” column and a form with a “zip” field that they actually mean the same €“ they are the same abstract concept. This allows machines to follow links and hence automatically integrate data from many different sources.

Semantic Web technologies can be used in a variety of application areas:

1.  Data integration, whereby data in various locations and various formats can be integrated in one seamless application.

2.  Resource discovery and classification to provide better, domain specific search engine capabilities

3.  Cataloging for describing the content and content relationships available at a particular Web site, page, or digital library.

4. Intelligent software agents to facilitate knowledge sharing and exchange.

5.  Content rating

6. Describing collections of pages that represent a single logical “document”.

7. Describing intellectual property rights of Web pages (see, eg, the Creative Commons), and in many others.

1.2 What are some of the major building blocks of the Semantic Web?

In order to achieve the goals described above, the most important is to be able to define and describe the relations among data (i.e., resources) on the Web.

Similar to using  hyperlinks on the current Web that connect the current page with another one, hyperlinks defines a relationship between the current page and the target.

One major difference is that, on the Semantic Web, such relationships can be established between any two resources, there is no notion of “current” page.

Another major difference is that the relationship (i.e, the link) itself is named, whereas the link used by a human on the (traditional) Web is not and their role is deduced by the human reader.

The definition of those relations allow for a better and automatic interchange of data. RDF, which is one of the fundamental building blocks of the Semantic Web, gives a formal definition for that interchange.

On that basis, additional building blocks are built around this central notion. Some examples are:

€¢  Tools to query information described through such relationships (eg, SPARQL)

€¢  Tools to have a finer and more detailed classification and characterization of those relationships. This ensures interoperability and more complex automatic behaviors. For example, a community can agree what name to use for a relationship connecting a page to one’s calendar; this name can then be used by a large number of users and applications without the necessity to redefine such names every time. (E.g., RDF Schemas, OWL, SKOS)

€¢  For more complex cases, tools are available to define logical relationships among resources and the relationships (for example, if a relationships binds a person to his/her email address, it is feasible to declare that the email address is unique, ie, the address is not shared by several persons). (E.g., OWL, Rules)

€¢  Tools to extract from, and to bind to traditional data sources to ensure their interchange with data from other sources. (E.g., GRDDL, RDFa)

 Ok. Are you getting very very sleepy on me?

Guess we better wrap this up for tonight.    Let’s finish off with a great video from Nova Spivack, creator of Twine Networks.

Nova Spivack – Semantic Web Talk from Nicolas Cynober on Vimeo.

Or if you prefer Power Point Slides to explain the Semantic Web

Nova Spivack’s Making Sense of the Semantic Web

His presentation is provided is licensed under the Creative Commons Attribution License. If you reproduce or redistribute in whole or in part, please give attribution to Nova Spivack, with a link to http://www.mindingtheplanet.net

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References:

W3C Semantic Web (2001). W3C Semantic Web Frequently Asked Questions. Retrieved March 5, 2008,  from  http://www.w3.org/2001/sw/SW-FAQ#What1

Spivack, Nova. (n.d.). Making sense of the semantic web.   Retrieved March 5, 2008, from http://www.mindingtheplanet.net

Spivack, Nova. (n.d.). Semantic Web talk.   Retrieved March 5, 2008, from http://www.vimeo.com/684381

For the last three months, I have been experimenting with various open source programs to try and deterimine the best way to build a collaborative community.  Here’s what I’ve come up with:

Simply my opinions:

WordPress: Plus
Extremely fast spiderability.   Beautiful clean code without a lot of hoopla.   Easy to read, update and navigate.   A lot of open source code available, used everywhere. Free templates available, easily changed out.   WordPress was used to make this blog.

WordPress: Negative
Would need to figure out how to transform from just a blog to a community blog & forum to be effective as a collective intelligence platform.

Joomla: Plus
Has a   lot of open source widgets that will plug in to let you run a community. Can look very flashy, and appealing for awhile, till the design grows tiresome.   Some free templates, mostly paid.

Joomla: Negative
 Unless you know how to redesign the plethora of less then pleasing templates out there, you will always feel dissatisfied.   Most people are not PHP programmers.   It’s not easy to figure out.   If you are a designer you mindset is towards creating design, not figuring out PHP code.   I have been  a designer since 1989.   Therefore I have certain hopes and aspirations for the look and feel of a community.   Despite spending quite a bit on template subscriptions, I have never found one that looked professional enough that I could live with.    Can be dangerous to upload components and modules from third parties.

Joomla control panels are just plain confusing.  I found myself constantly trying to  figure out where certain user areas were within the control panel, and how to access the modules to get the information in.   When  beginning with  someone else’s idea of how something is designed, you are at a disadvantage from the very beginning.   I purchased two e-books on how to customize Joomla, and even a Dreamweaver addon.   I frankly didn’t have the patience to muddle through them though, especially when I realized Google just didn’t care.   It’s difficult to get spidered – it’s just that simple.   I even submitted an xml feed direct to Google.  If you look at the code behind on a Joomla site you realize what a jumble it really is.

Wikimedia: Positive
Looks just like Wikipedia, because it’s made by the same open source individuals.  Most people are familiar with this interface, and that familiarity  brings comfort and efficiency.   Provides for true collaboration as users provide information and others help to edit.   Spiders very efficiently.   Can translate to various languages quickly and easily.

Wikimedia: Negative
Difficult to format at times.   However,    if the Web master provides  quick tip page it helps considerably.    Whomever can do whatever they want to your pages, unless you intentionally set up permissions or log in information.

 Drupal: Plus
If you are really intent on starting a community,   I would probably have to go with Druple.  Sure the templates aren’t as showy as Joomla, but the real intent for a research collaborative community is to get good clear information out there.   Druple is used by Adobe, the United Nations, and a host of others as their CMS systems of choice.   There is a reason.   It’s simple to use, and it works.

Drupal spiders easily.   It allows for multiple blogs, and a forum.   I found it to be much more intuitive to use then Joomla without having to use a lot of suspicious looking third party components to get it to do what I wanted.

Conclusions

1. Joomla – Looks flashy, but that’s about it.   Not that easy to use, and doesn’t spider well.   Be prepared to be bewildered on the components and modules, and where your content is going.   Templates difficult to work with, and not very sophisticated in terms of quality design.   Be prepared to be disappointed when trying to massage your information inside someone else’s template.   Things can go terribly wrong fast – without any real show of  support  even though you’ve  paid the template provider.

2. Wordpress – Very easy to use, extremely easy to spider.   Even my 69 year old mother uses it.    Google realizes when you have a Wordpress blog installed and will come by very often to pick up your new information.   In fact, I’ve noticed within 15 minutes information is being posted up on Google. Would have to open up comments though for collaboration.   Leaves door open for spam then.   Thousands of templates to choose from that are free.  Google doesn’t like it if you don’t regularly feed your blog with content, and I mean just about every other day.

3. Wikimedia – Fairly easy to use.   Comfortable format for people.   Easily spidered.   Good for collaborative work. Translates to different languages quite easily.   Can customize the look with style sheets.   Not as flashy, but doesn’t matter if you are just trying to provide good usable, clean information.

4. Drupal – Straightforward.   Good for community building.   If you are a designer, or an idea person but just not a programmer you can still get going pretty well.   Spiders  excellent.   Can have multiple blogs, and forums right off the bat.   Templates are ok, and can still customize if you understand PHP, or stylesheets.

References for better understanding:

Why use Drupal
Download Wikimedia
Joomla vs Drupal

Google Talk Impementing Drupal: