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-
- Brain Waves
- "Viewpoint"
- November 1986 AI EXPERT
-
- by Alex Jacobson, President,
- Inference Corporation
-
-
-
- Expert systems technology enables computer to use human
- expertise, judgments and knowledge to solve business problems in
- an emulation of the way human experts do. There is considerable
- evidence to suggest that this technology, when applied to a well-
- focused, sufficiently well-defined domain of interest (e.g.,
- authorization of a specific type of credit card, diagnosing of
- faults in a specific piece of equipment, scheduling of a specific
- fleets of vehicles in a specific geographic area or configuring
- of a specific set of machines on a specific factory floor) can
- provide human workers who operate in the targeted domain with
- computer support at levels of performance equal to or better than
- the best human experts in the domain.
-
- The benefit of this capability is to enable computers to
- formulate decisions, to draw conclusions and to propose actions
- in response to the wide variety of unstructured or poorly
- structured problems with which only humans could contend
- heretofore. As a result, this technology makes it possible for
- computers to do the same sorts of tasks that professionals and
- white collar workers presently do in the work force --a necessary
- accomplishment if these workers are to receive automation. The
- significance of these capabilities is more far reaching than the
- technical content, per se, implies. The reason is that expert
- systems technology has matured at a time when the computer
- industry as a whole is moving through a major transition. The
- computer industry has, over the past 30 years, fulfilled much of
- its promise in automating clerical level functions (typing
- drafting, bookkeeping, inventory management, listings, records
- keeping etc.). Business and industry is now focusing attention on
- strategic uses of computers in mission-critical applications.
- These applications, a prime example of which is the American
- Airlines Saber System, can provide a major competitive edge to
- companies able to conceive and to implement them. White collar
- workers implement business strategies, hence it is this segment
- of the work force that will be targeted for computer automation
- as strategic uses of computers are undertaken in business. Expert
- systems technology is a critical component for delivering this
- automation to the professional, technical and administrative
- workers who implement mission-critical applications in business
- and industry. This propitious timing between a new capability
- (i.e., expert systems) and a new requirement (i.e., mission-
- critical applications of computers) explains the unusual sense of
- importance that is attributed to expert systems technology
- throughout the world.
-
- Expert systems technology is primarily targeted for use in
- applications software and in software tools that support the
- development and operation of applications and systems software.
- The fundamental difference between an expert system and a
- traditional application program is that such an expert system is
- rich in knowledge about the solution of problems in the
- application domain in which the expert system operates; whereas
- traditional applications are rich in the procedural knowledge
- that instruct the computer how to process data to solve the
- problems in the domain in question. It is this richness in
- knowledge that makes expert systems an enabling technology for
- the use of computers in mission-critical applications.
- Nevertheless, expert systems contain procedural knowledge with
- which to instruct the computer and traditional applications
- contain knowledge about the problem solving. It is the higher
- density and the greater extent of knowledge about problem solving
- that distinguishes expert systems from traditional applications
- programs, and provides them with their unusual functional power.
-
- This fundamental difference leads to all of the basic differences
- in the underlying tools, technology and programming methodologies
- (i.e., knowledge engineering) that set the practice of expert
- systems apart from that of conventional software engineering. In
- order to elicit deep and extensive knowledge about problem
- solving in any but most straightforward industrial task areas, it
- is necessary for the software engineer to develop the expert
- system by means of an iterative or evolutionary development
- process. The reason is that humans cannot divulge the deep and
- subtle levels of knowledge about their problem solving expertise
- that industrial class expert systems require, and are able to use
- effectively in a straightforward debriefing process. Rather, it
- is necessary that the software engineering methodology be capable
- of supporting a development regimen that permits knowledge
- obtained by debriefing to be built into an operating partial
- application so that areas of mission knowledge (i.e., knowledge
- not accessible by straightforward interview) can be identified
- and then added to the partial application to create a more
- complete, yet, perhaps still partial application, which can then
- be used to find still less accessible areas of germane knowledge
- which in turn can be added to the system, and so on. This method
- of evolving the expert system into existence is called "bottom-
- up-discovery", and is the distinguishing feature of knowledge
- engineering.
-
- Expert systems tools contain the AI technology required to
- support the process of knowledge engineering for building expert
- systems. They contain the structures required to store a variety
- of different types of knowledge paradigms, an inferencing engine
- that permits this knowledge to be used as the system evolves even
- though the knowledge is added to the system incrementally,
- systems software that allows the knowledge engineering to browse,
- modify, add, delete, understand or otherwise manipulate the
- knowledge in the evolving knowledge base, and tools to assist the
- knowledge engineer to build the expert system including the user
- interface of the resulting expert systems. These tools serve the
- purpose of accelerating the pace with which this new technology
- can be effectively applied.
-
- Expert systems technology is basically a software technology.
- While it has almost exclusively been developed in Lisp, and, in
- recent years, Lisp machines, like all other software technologies
- it is intrinsically portable to other languages and to other
- classes of computers. This is of vital importance. To realize
- their full potential, expert systems must fulfill their role in
- mission-critical applications. This requires that expert systems
- operate effectively and efficiently in conjunction with existing
- computer environments. Hardly any of these existing environments
- support Lisp or incorporate Lisp machines. Since expert systems
- technology is portable, it is clear that it must be ported to
- mainstream computers and connected to mainstream software at the
- levels of traditional languages, systems software and
- applications programs. This requirement cannot be evaded -- nor
- need it be.
-
- Finally, there is the question of culture. Expert systems are
- computer applications that arise from a technology culture that
- is substantively different from the culture that has created
- traditional computer applications. Cross culture communication is
- always difficult. It will be no different in this instance. It
- promises to be one of the more formidable obstacles to
- commercialization of expert systems. Not only does the
- applications programming community face the challenge of
- assimilating this new technology, but business operations
- management as well as end-users also must become both familiar
- and comfortable with expert systems and their implications as
- these systems move into the front office. Management faces the
- challenge of managing business practices in which the underlying
- logic of the practice has been made explicit for the first time
- and for which accountability of performance is documented with
- the scrupulousness of which only computers are capable. End-users
- who have never before used computers must become comfortable with
- these new mechanical assistants -- no simple task given the
- anxiety often incurred by computers in people who have no
- predilection for machines.
-
- Although these obstacles are formidable, they can and will be
- transcended. The benefits of industrial scale expert systems to
- the businesses that employ them promise to be too great for these
- transitional burdens to be anything but passing challenges.
- DP/MIS workers, end-user computing programmers, applications
- software vendors, all will benefit from their efforts to adopt
- this new technology. Therefore, expert systems software will
- inevitably lose its singular name and become "just another"
- commercial software technology as the computer industry continues
- to support the growth of business throughout the world.
-
- commercial software technology as the computer industry continues
- to support the growth of business