Communicating the Value of Cisco

Communicating the Value of Cisco.com Demystifying the Semantic Web; Is Migration Right For You? By Kristen Brennan April 14, 2003 San Francisco

What is a Semantic Website? The term “Semantic Web” was first coined by Tim Berners-Lee, Director of the World Wide Web Consortium. He views the Semantic Web as the next evolutionary step for the World Wide Web, which he invented in 1989.

What is a Semantic Website? Imagine two librarians. The first has memorized the title and location of every book in her library, but never opened one. She could find you a copy of “Gone With The Wind,” but only if you knew the exact name and spelling. The second librarian has read and understood every book. She could find you “the book about Scarlett O’Hara,” or “a romance set in the antebellum South,” or even “a great classic for young girls.” A Semantic Web is like the librarian who has read the books. It can go beyond mere information retrieval to intelligent decision-making.

What Distinguishes a Semantic Website? Syntactic Root: Greek Syntassein, meaning “to arrange” Definition: A syntax is a scheme for naming and arranging a group of elements. Usage: Websites have historically been built on the syntactic model, which “thinks” in terms of individual elements, but has no innate awareness of how they relate. Semantic Root: Greek sEma, meaning “sign” Definition: A semantic model is a way of describing the meaning of elements in terms of their relationships with each other. Usage: A website built with a semantic model “thinks” in terms of relationships. Those relationships and the elements which they describe form an ontology. Semantic websites Dynamic syntactic websites Sophistication Static syntactic websites 1970s 1990s Today 1980s

What is an Ontology? The word “Ontology” comes from the New Latin ontologia, which means “the study of being.” It refers to the branch of philosophy which attempts to describe the nature of existence. In the computer industry an ontology is a formal model describing the fundamental elements of a system in a way that a computer can understand. The term was popularized by researchers into Artificial Intelligence. They believe that organizing a computer’s information into an ontological model grants the machine a crude form of ‘self awareness,’ which enables it to make decisions more intelligently. Web ontologies are nearly always built using a taxonomy and a set of inference rules.

What is a Taxonomy? A Taxonomy is a classification system organized by parent-child relationships. The word is traditionally applied to the tree of interrelationships of animal species (as in this taxonomy of birds).

What Are Inference Rules? Computer scientists borrowed the term “formal system” from mathematics, specifically the field of logic. A formal system contains both Axioms and Rules of Inference (or ‘Inference Rules’). An Axiom is a rule, such as “Dogs may not visit the Beach.” Inference Rules provide a system for deriving child-rules from axioms. So if Spot is a dog, and the axiom is “Dogs may not visit the Beach,” then we may infer the rule “Spot may not visit the Beach.”

What Are Semantic Relationships? For a machine to understand how to make inferences, it must know that Spot is a dog. In other words, it must explicitly understand the relationship between “Spot” and the concept of “Dog.” The machine must also know what type of relationship the two share – in this case “Species.” When two or more objects are defined in terms of their relationship with each other, and that relationship is of a recognized type, we have described the relationship semantically. A fully-semantic website is one in which every element is described semantically.

Advantages of Semantic Websites Websites based on a semantic model offer significant advantages over those built on syntactic models: Syntactic Model Semantic Model The semantic model accommodates changes with a modest resource cost which remains constant. This results in a lower TCO (Total Cost of Ownership): The resource costs for fully iterating changes across a syntactic website grow exponentially; the more pages, the greater the cost. Semantic models can easily present data in whichever perspective is most appropriate: business needs, marketing, support, or even custom-tailored to each individual user. This provides flexibility of perspective. Syntactic web-models are usually organized in a fixed products-and-services tree. Syntactic websites are “hard-wired” to a single model which may become outdated. Semantic websites may be reorganized quickly and easily. They may therefore accommodate unforeseen business needs of the future.

Advantages of Semantic Websites The most obvious advantage of the semantic model is Flexibility to Grow: the resource cost of accommodating change remains constant, as contrasted with the exponential growth rate of resource costs for maintaining a syntactic website. In one legend Chess was introduced into Europe by a traveling Fool. The King was so pleased with the game that he offered the Fool as much grain as he could carry. The Fool asked instead for a chessboard with a single grain of wheat in the first square, and double the amount in every subsequent square. The King, thinking he was getting a bargain, agreed. 1+2^63 is such an enormous number that the Fool ended up owning the entire kingdom. The moral: "Any exponential growth will eventually outstrip any linear growth." For large corporate sites who plan to grow, the question is not “Should our website migrate to a semantic model?”, but “When should our website migrate to a semantic model?”

Semantic Website Challenges The semantic website model also offers challenges: initial setup is more expensive, the learning curve for those who maintain the system is steeper, and the organizational hurdles can be significant. Tokugawa Ieyasu, the world’s first Shogun, faced similar problems when he attempted to unify the various territories of Japan into a single nation in the early 1600s.

Semantic Website Challenges Tokugawa first created infrastructure, connecting all of Japan with well-maintained, well-policed roads for the first time. Soon thereafter he encouraged a common culture by mandating Japanese as the national language. He faced strong resistance from those who wished to continue speaking their regional languages.

Semantic Website Challenges Japanese Contrast with China, which has far greater resources; Because the Chinese still speak hundreds of languages, China often behaves like many tiny nations rather than a single great nation. Tokugawa persevered, and his unification process ultimately became one of the primary elements which allowed Japan to become a consistant economic force on the world stage.

Should Your Site Migrate? Factors to Consider Initial Setup Costs TCO (Total Cost of Ownership Semantic websites cost more initially… Syntactic model: The resource cost for each change increases exponentially Cost Syntactic Model Semantic Model Significant Feature Upgrade Costs Resource cost for each change …but major upgrades are much cheaper. Semantic model: costs level off after migration point Cost Size of website (in pages) Semantic Model Syntactic Model

Case Study: Google.com Google.com takes advantage of what might be called a limited semantic model. That is, they derive a semantic model of the entire World Wide Web, which empowers their search engine with an ability to perform queries with far more intelligence than any of their competitors. However, because Google’s model is derived from the Web rather than driving it, Google is unable to take advantage of some of the best features of semantic modeling: they cannot mandate a single vocabulary for the entire web. Even more importantly, they cannot decide which relationships should define a page, but must rely solely on which relationships already exist – primarily links between pages. Semantic Syntactic

Case Study: Google.com Total Search Hours (in millions) As of February 2002 Even this limited semantic model has demonstrated unprecedented advantages. Search engine performance is increasingly measured by the amount of time people spend using the tool. By this metric, Google is almost twice as popular as their nearest competitor. Semantic modeling offers the potential to dramatically improve usability.

Case Study: Amazon.com Like Google, Amazon takes advantage of what might be called a limited semantic model. But instead of working from a derived semantic model, they add a semantic layer on top of what is essentially a syntactic database. Amazon creates this semantic layer by modeling the relationships between purchases made by their customers. So for instance, if most people who buy Harry Potter books purchase the entire series, and you've bought all but the latest, there's a good chance you'll buy that one, too.

Toward a Mature Semantic Website How does one avoid the risk of creating a bottleneck problem when migrating to a semantic model? That is, if all web changes must be made to a single engine owned by a single group, how can the system best satisfy those groups who have grown to expect complete autonomy over their own web areas? To understand this question, let’s revisit the typical syntactic web, which resembles a series of “silos”: Marketing; Product Support Marketing; Pricing Marketing; Advertising Data is decentralized Pricing information for 7200 Router Support information for 7200 Router Marketing information for 7200 Router …these silos meet the needs of each individual group, but because they’re not connected, there is duplication of effort (at best) or even inconsistency of information. These problems grow worse as the website expands.

Toward a Mature Semantic Website Creating a Semantic Model unifies these silos into a single system: Marketing; Product Support Marketing; Pricing Marketing; Advertising Data is decentralized Metadata is centralized Semantic Engine ALL information for 7200 Router …eliminating duplication of effort (thus saving $) and improving navigation consistency. However, the individual groups may feel limited by loss of autonomy over their web areas.

Toward a Mature Semantic Website …which is solved through creation of Semantic Engine Clients: Marketing; Product Support Marketing; Advertising Marketing; Pricing Data is decentralized Metadata is centralized Semantic Engine Access to metadata is decentralized Financial Client Marketing Client IT Client …thus providing a “best of both worlds” solution.

Toward a Mature Semantic Website For each major internal client of the semantic engine, it may be possible to first capture a quick win with a broad rules-based tool (“Surface the best-selling product in each category on that category’s homepage”). Ultimately each client will seek a more granular tool (“Put a particular link on a particular page.”). Internal clients get the flexibility, autonomy and quick-turnaround they’ve always enjoyed, and the company as a whole takes advantage of the semantic model. As with Tokugawa’s mandate of a single-language Japan, unifying an Enterprise Site requires strong leadership and the ability to weather short-term growing pains in the interest of much greater long-term advantages. Marketing Rules Client Financial Rules Client IT Rules Client

Toward a Mature Semantic Website Financial IT Marketing; Product Support Marketing; Pricing Marketing; Advertising Semantic Engine The semantic model-driven website is only one of the benefits to creating a company-wide ontology. Ultimately, the Semantic Engine can be expanded to empower Business Intelligence not only between a company and their web-audience, but among the various internal divisions of the company. Company-wide semantic consensus makes that company smarter.

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Communicating the Value of Cisco