Knowledge base: Difference between revisions

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The first knowledge-based systems had data needs that were the opposite of these database requirements. An expert system requires structured data. Not just tables with numbers and strings, but pointers to other objects that in turn have additional pointers. The ideal representation for a knowledge base is an object model (often called an [[Ontology (information science)|ontology]] in [[AI|artificial intelligence]] literature) with classes, subclasses and instances.
 
Early expert systems also had little need for multiple users or the complexity that comes with requiring transactional properties on data. The data for the early expert systems was used to arrive at a specific answer, such as a medical diagnosis, the design of a molecule, or a response to an emergency.<ref name="hayes"/> Once the solution to the problem was known, there was not a critical demand to store large amounts of data back to a permanent memory store. A more precise statement would be that given the technologies available researchers compromised and did without these capabilities because they realized they were beyond what could be expected and they could develop useful solutions to non-trivial problems without them. Even from the beginning, the more astute researchers realized the potential benefits of being able to store, analyze, and reuse knowledge. For example, see the discussion of Corporate Memory in the earliest work of the Knowledge-Based Software Assistant program by [[Cordell Green]] et al.<ref>{{cite journal |last=Green|first=Cordell|author2=D. Luckham |author3=R. Balzer |author4=T. Cheatham |author5=C. Rich |title=Report on a knowledge-based software assistant|journal=Readings in artificial intelligence and software engineering |year=1986 |pages=377–428 |url = http://dl.acm.org/citation.cfm?id=31893 |accessdate=1 December 2013|publisher=Morgan Kaufmann }}</ref>
 
The volume requirements were also different for a knowledge-base compared to a conventional database. The knowledge-base needed to know facts about the world. For example, to represent the statement that "All humans are mortal". A database typically could not represent this general knowledge but instead would need to store information about thousands of tables that represented information about specific humans. Representing that all humans are mortal and being able to reason about any given human that they are mortal is the work of a knowledge-base. Representing that George, Mary, Sam, Jenna, Mike,... and hundreds of thousands of other customers are all humans with specific ages, sex, address, etc. is the work for a database.<ref>{{cite book |last=Feigenbaum|first=Edward|title=The Fifth Generation: Artificial Intelligence and Japan's Computer Challenge to the World |url=https://archive.org/details/fifthgeneration00feig|url-access=registration|year=1983|publisher=Addison-Wesley|location=Reading, MA|isbn=0-201-11519-0|page=[https://archive.org/details/fifthgeneration00feig/page/77 77]|quote=Your database is that patient's record, including history... vital signs, drugs given,... The knowledge base... is what you learned in medical school... it consists of facts, predicates, and beliefs...}}</ref><ref>{{cite book |last=Jarke|first=Mathias|title=Logic, Databases, and Artificial Intelligence |url = http://www.dfki.de/~wahlster/Publications/KBMS_Requirements_of_Knowledge-Based_Systems.pdf |year=1978|publisher=Springer |location=Berlin |chapter=KBMS Requirements for Knowledge-Based Systems}}</ref>