Foreword

For my entire professional life (and I'm getting old enough not to want to admit how long that has been), I've been working in the area of semantics in one form or another. For the past decade, I've focused on bringing this work to business practices and, most importantly, to the World Wide Web. Even before the term "Semantic Web" had been coined and before the World Wide Web was the global phenomenon it has become, a number of us realized that bringing semantics to the emerging web was a natural extension, necessary if we were going to create a web that went beyond simple text documents and got to the really good stuff. The fact that you're reading this book today demonstrates the emerging realization that there's a lot more this Web thing could and should be doing—and the technology to get it there is now within reach.

I've been very lucky to live through this transition, sometimes with the true joy of being one of the agents of change, and other times watching in bewilderment as others brought new technologies to the table that I, in my far less than infinite wisdom, predicted were still years away. In the mid 1990s, my research group created a language called SHOE, which stood for "Simple HTML Ontology Extensions." When I started presenting that work, I was often warned, "Stay away from the O-word—these folks won't get it." Two years ago, the World Wide Web Consortium announced the Web Ontology Working Group, and it rapidly became one of the consortium's largest working groups. Nowadays, I am invited primarily to talk about ontologies— quite a change in a brief time.

Similarly, not that long ago, I was warned not to scare the Web Services people by talking about semantics. Now, groups interested in "Semantic Web Services" commission a large proportion of my speaking engagements. The world is changing fast and, for better or worse, semantics is at the heart of it.

One of the reasons semantics is so important is that it may spawn some of the first technologies that help us deal with the Tower of Babel that human communication has become. Consider the following thought experiment: A large group of experts and specialists (let's say a thousand of them) from a wide range of fields are brought together by some unnamed billionaire. They are told they have a year to demonstrate a solution to a problem of world significance—cost is no object, and they'll all be highly paid for their time. A year later, it is almost inevitable that the group will have developed into many subgroups, each working on a different approach to demonstrating the solution and each using a jargon that is hard for the others to understand! The group will have splintered into the proverbial blind men approaching the elephant, each subgroup attacking different pieces of the puzzle and each subgroup unable to explain to the others why their approach is obviously the right one.

On reflection, the reason for this is pretty clear. As people start forming communities and attacking the problem, their approaches to the solution will vary. Some will think that a demonstration requires a theoretical proof; some that a demonstration is a proof of concept program or device; some that to demonstrate an effect you must run experiments with groups of human subjects; and others that a compelling demonstration requires "facts on the ground," where it is obvious to external observers that the approach has helped. As these groups separate, they must develop more detailed communication within each subgroup, and the language diverges. New words aren't usually invented, rather new meanings are imposed on the words and phrases already being used (for more on this phenomena, see Chapter 4).

Of course, this problem is just as bad for the many of us who've been working in the semantics area. We've created our own polyglot of tongues that are being used differently by researchers with backgrounds in artificial intelligence, database integration, information retrieval, Web services, Web design, thesaurus creation, linguistics, philosophy, engineering, and many others. Unfortunately, as semantics-based technologies and the Semantic Web become more and more prevalent, the smart manager will have to speak these new languages, and the informed decision-maker will have to understand what is real and what is the inevitable hype that follows "the next big thing." A book explaining the terms used in this new set of worlds, defining them in a plain-speaking way, and clearly making the business case for their use, was clearly needed.

So, join me in thanking Dave McComb for creating such a book. He will explain the ideolect (see Chapter 4) of the semantic practitioner, make the case for the practice, and prescribe the first steps for getting started in this strange new world—and not a minute too soon, because your competitors are also learning about the edge it can give them over you.

So, thanks, Dave. And to you, the reader, welcome to the world we invite you to help us create.

Jim Hendler
Director, Semantic Web and Agent Technologies
Maryland Information and Networks Dynamic Labs University of Maryland
and Co-chair, W3C Web Ontology Working Group