p.491 Knowledge is very distinct from data and information in the information
technology context... Whereas data are a collection of facts, measurements, and statistics, information is organized
or processed data that are timely (i.e., inferences from the data are drawn within the time frame of applicability) and accurate
(i.e., with regard to the original data)... Knowledge is information that is contextual, relevant, and actionable...
Having knowledge implies that it can be exercised to solve a problem, whereas having information does not carry the same connotation.
An ability to act is an integral part of being knowledgeable... knowledge provides a higher level
of meaning about data and information. It conveys meaning
p.542 Heuristics consists of intuitive knowledge, or rules of thumb, learned
from experience. Its role in AI is seen in the following definition: Artificial intelligence is the branch of computer science
that deals with ways of representing knowledge using symbols with rule-of-thumb, or heuristic, methods for processing information
(Encyclopaedia Britannica).
p.542 As an alternative to heuristics, artificial intelligence also builds reasoning capabilities that can
build higher-level knowledge from existing heuristics. This reasoning consists of inferencing from facts and rules using heuristics
or other search approaches.
p.549 Typically, human experts are capable of doing the following:
- Recognizing and formulating the problem
- Solving the problem quickly and correctly
- Explaining the solution
- Learning from experience
- Restructuring knowledge
- Breaking rules if necessary
- Determining relevance
- Degrading gracefully (being aware of one's limitations).
p.556 The knowledge base contains the relevant knowledge necessary for understanding, formulating,
and solving problems. It includes two basic elements: (1) facts, such as the problem situation and the theory of the problem
area, and (2) special heuristics or rules that direct the use of knowledge to solve specific problems in a particular domain.
(In addition, the inference engine can include general purpose problem-solving and decision-making rules.) The heuristics
express the informal judgmental knowledge in an application area. Knowledge, not mere facts, is the primary raw material
of expert systems.
p.566 The "brain" of the ES [expert system] is the inference engine,
also known as the control structure or the rule interpreter (in rule-based ES). This component is essentially
a computer program that provides a methodology for reasoning about information in the knowledge base and on the blackboard,
and for formulating conclusions. This component provides directions about how to use the system's knowledge by developing
the agenda that organizes and controls the steps taken to solve problems whenever consultation takes place.
p.556 The blackboard is an area of working memory set aside as a database for the description
of a current problem as specified by the input data; it is also used for recording intermediate hypotheses and decisions.
Three types of decisions can be recorded on the blackboard: a plan (how to attack the problem), an agenda (potential actions
awaiting execution), and a solution (candidate hypotheses and alternate courses of action that the system has generated thus
far.
