Knowledge Engineering (Errors in Development Stage ( Expert’s Error …
Errors in Development Stage
Expert’s knowledge may be erroneous, propagating errors throughout the entire development process.
◦ Formal procedures may be necessary to certify expert
◦ Technique panels can scrutinize expert’s knowledge
The meaning of knowledge may not be properly communicated to knowledge engineer, or knowledge may be misinterpreted.
Knowledge base may be corrupted by entering incorrect form of a rule or fact
Inference engine errors
may result from errors in pattern matching, conflict resolution, and execution of actions.
Inference chain errors
may be caused by erroneous knowledge, semantic errors, inference engine bugs, incorrect specifications of rule priorities, and unplanned interaction among rules.
Limits of Ignorance Errors
Specifying the limits of ignorance of the system. Unless the expert system is programmed to handle uncertainty it would continue to supply answer
Selecting the Appropriate Problem
Why build the expert system?
Need clear identification of the problem, expert, and users.
What is the payoff?
What is the return on investment in money, increased efficiency, or any other advantages.
What tools are available to build the system?
How much will it cost?
The cost is dependent upon the people, resources, and time devoted to its construction.
Also the costs of hardware and software as well as training need to be considered.
Data, Information, Knowledge & KBS
isolated facts such as individual measurements. Items of data have no meaning on their own; they do not signify anything and are useless unless placed in some sort of context
E.g: 10,1.56672, mary, red,100,000
consists of symbols such as text or numbers, but this time there is some meaning associated with the symbols. Because of this added meaning, the information now has some use or value
E.g: 10⁰C, RM100000, the red apple
consists of symbols, the relationship between them and rules or procedures for manipulating them. It adds context to the information, providing greater meaning and is therefore of much greater use and value
process of ◦ designing ◦ building ◦ installing an expert system or other knowledge- based system. In other words, the whole process of making a KBS, from beginning to end.
Commonly used to describe the process of KBS development in any field, whether it be in the public or the private sector, in commerce or in industry.
Stages in the Development of Expert System
How will the system be developed
It depends on:
◦ Resources provided,
◦ How the process is organized and managed.
◦ planning, scheduling, chronicling, analysis
product configuration management
◦ product management ◦ change management
◦ Forecast needs for resources
◦ acquisition resources
◦ assignment of responsibilities
◦ identification of critical resources
“How will the system be delivered?”
◦ Should be considered in earliest stages of development
◦ Integration with existing programs
“How will the system be maintained and evolve?”
◦ Performance is dependent on knowledge/expertise
◦ Performance must be maintained
New knowledge will be acquired
Old knowledge will be modified
◦ Extracting knowledge from people
◦ Representing it in some form
◦ Including it in a computer program which makes use of the knowledge
◦ Validating the software system which has been produced
Engineering, Software Engineering and Knowledge Engineering
the science, skill, and profession of acquiring and applying scientific, economic, social, and practical knowledge, in order to design and also build structures, machines, devices, systems, materials and processes
an engineering discipline that concerned with all aspects of software production from the early stages of system specification to maintaining the system after it has gone into use
The process of developing KBS which includes:
Acquiring from experts the knowledge that is to be used in the system
Choosing appropriate method of representing the knowledge in a symbolic form
Implementation in computer language