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Introduction to Artificial Intelligence & Expert Systems




                    Notes          3.4.2 Knowledge Acquisition Problem

                                   The preceding section provided an idealized version of how ES projects might be conducted. In
                                   most instances, the above suggestions are considered and modified to suit the particular project.
                                   The remainder of this section will describe a range of knowledge acquisition techniques that
                                   have been successfully used in the development of ES.

                                   Operational Goals

                                   After an evaluation of the problem domain shows that an ES solution is appropriate and feasible,
                                   then realistic goals for the project can be formulated. An ES’s operational goals should define
                                   exactly what level of expertise its final product should be able to deliver, who the expected user
                                   is and how the product is to be delivered. If participants do not have a shared concept of the
                                   project’s operational goals, knowledge acquisition is hampered.

                                   Pre-training

                                   Pre-training the knowledge engineer about the domain can be important. In the past, knowledge
                                   engineers have often been unfamiliar with the domain. As a result, the development process
                                   was greatly hindered. If a knowledge engineer has limited knowledge of the problem domain,
                                   then pre-training in the domain is very important and can significantly boost the early
                                   development of the ES.

                                   Knowledge Document

                                   Once development begins on the knowledge base, the process should be well documented. In
                                   addition to tutorial a document, a knowledge document that succinctly state the project’s current
                                   knowledge base should be kept. Conventions should be established for the document such as
                                   keeping the rules in quasi-English format, using standard domain jargon, giving descriptive
                                   names to the rules and including supplementary, explanatory clauses with each rule.

                                       !

                                     Caution The rules should be grouped into natural subdivisions and the entire document
                                     should be kept current.

                                   Scenarios

                                   An early goal of knowledge acquisition should be the development of a series of well developed
                                   scenarios that fully describe the kinds of procedures that the expert goes through in arriving at
                                   different solutions. If reasonably complete case studies do not exist, then one goal of pre-training
                                   should be to become so familiar with the domain that the interviewer can compose realistic
                                   scenarios. Anecdotal stories that can be developed into scenarios are especially useful because
                                   they are often examples of unusual interactions at the edges of the domain. Familiarity with
                                   several realistic scenarios can be essential to understanding the expert in early interviews and
                                   the key to structuring later interviews. Finally, they are ultimately necessary for validation of
                                   the system.

                                   Interviews

                                   Experts are usually busy people and interviews held in the expert’s work environment are
                                   likely to be interrupted. To maximize access to the expert and minimize interruptions it can be




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