Appendix A: Quick Reference

This appendix is meant to provide a quick reference to some of the more important topics covered in this book.

Semantics

Semantics is the study of meaning. It is of interest to us here because as we automate our business processes we cannot help but deal with the meaning of the information we are capturing and processing.

Semantics in business systems has been very informal up to this point. We "capture" requirements, expressed in "terms" that we define, yet the meaning of these terms is not very rigorous. As a result, systems are much more complex than they need to be, they are inflexible, and they tend to be difficult to integrate with other systems, because each system deals with similar but not identical semantic definitions for related terms.

Our best hope for dealing with our semantic overload is to spend more time understanding the meaning of the information we are dealing with. There are many techniques for doing this, and this book is just an introduction to these techniques. Some of the key approaches described herein include the following:

• Reference ontologies—An ontology is an organized description of the meaning of concepts and terms in a given domain. One of the first approaches that leads to shared meaning is to commit to a known or accepted ontology.

• Semantic primitives—Linguists and anthropologists have concluded that there are a small number of "semantic primitives" that are so fundamental that they are found in all languages and cultures, and are so basic that they defy definition in other terms. We postulate that there is a comparable small subset of semantic primitives that form the basis of all definable business objects. Such a set of semantic primitives, once well understood, would allow systems to communicate even if one system didn't know all the terms used by the other system. A full treatment of this topic is beyond the scope of this book; the concept is introduced in Chapter 9.

• Formal methods—There has been a great deal of work, mostly academic, using formal methods to create provably correct inferences from given starting points. This work is encouraging for the implications it will have on large-scale use of semantics and ontologies.