Technology
A Model of Inexact Reasoning in Medicine
Shortliffe, E.H. | Buchanan, B.G.
Reprinted in Readings in Uncertain Reasoning, G. Shafer and J. Pearl, eds., pp. 259-273, San Mateo, CA: Morgan Kaufmann Publishers, Inc., 1990.See also: Stanford Center for Biomedical Informatics Research (BMIR).… quantifying confirmation and then manipulating the numbers as though they were probabilities quickly leads to apparent inconsistencies or paradoxes. Carl Hempel presented an early analysis of confirmation (Hempel, 1965), pointing out as we have that C[h,e] is a very different concept from P(hle ). His famous Paradox of the Ravens was presented early in his discussion of the logic of confirmation. Let hl be the statement that "all ravens are black" and h2 the statement that "all nonblack things are nonravens." Clearly hi is logically equivalent to h,2. If one were to draw an analogy with conditional probability, it might at first seem valid, therefore, to assert that C[hl,e] = C[h2,e] for all e. However, it appears counterintuitive to state that the observation of a green vase supports hi, even though the observation does seem to support h,2. C[h,e] is therefore different from P(hle) for it seems somehow wrong that an observation of a vase could logically support an assertion about ravens. Another characteristic of a quantitative approach to confirmation that distinguishes the concept from probability was well-recognized by Carnap (1950) and discussed by Barker (1957) and Harrd (1970). They note it is counterintuitive to suggest that the confirmation of the negation of a hypothesis is equal to one minus the confirmation of the hypothesis, i.e., C[h,e] is not 1 - C[-qh,e]. The streptococcal decision rule asserted that a gram-positive coccus growing in chains is a Streptococcus with a measure of support specified as 7 out of 10. This translates to C[h,e]=0.7 where h is "the organism is a Streptococcus" and e is the information that "the organism is a gram-positive coccus growing in chains." As discussed above, an expert does not necessarily believe that C[mh,e] = 0.3. The evidence is said to be supportive of the contention that the organism is a Streptococcus and can therefore hardly also support the contention that the organism is not a Streptococcus. Ch.13 of Mycin Book; revised from Math. Biosci. 23:351-379
Some methods of controlling the tree search in chess programs
Adelson-Velsky, G. M. | Arlazarov, V. L. | Donskoy, M. V.
Research in computer chess has been active for over three decades. Over that period, computer chess has fallen from the position of being a prominent research application in artificial intelligence to a peripheral area. In this paper, we take a retrospective look at what has been accomplished, in order to understand where the field is today and where it is headed tomorrow. Whereas the past has often been clouded by engineering passing as science, misspent effort for short-term gains, and research results with little applicability to other domains, there is evidence that computer chess is emerging from the shadow of its past and may now be recapturing some of its lost stature in the research world.
Preference semantics
This dissertation describes a computational system for the analysis of English prose under the Preference Semantics theory of language understanding. The two main areas of investigation are these: (1) the design and implementation of a series of programs for extracting semantic information from a machine-readable dictionary, with this semantic information in a form suitable for use by a subsequent semantic analysis program, and (2) the design and implementation of a semantic analysis program that accepts short English texts and creates a corresponding representation from them. The resulting representation is in a suitable form, such that other Artificial Intelligence programs can use it as a knowledge source.
Adaptation in Natural and Artificial Systems
John Holland's pioneering book Adaptation in Natural and Artificial Systems [1975, 2nd ed. 1992] showed how the evolutionary process can be applied to solve a wide variety of problems using a highly parallel technique that is now called the genetic algorithm. The genetic algorithm transforms a population of individual objects, each with an associated fitness value, into a new generation of the population using the Darwinian principle of reproduction and survival of the fittest and naturally occurring genetic operations such as crossover (recombination) and mutation. Each individual in the population represents a possible solution to a given problem. The genetic algorithm attempts to find a very good or best solution to the problem by genetically breeding the population of individuals. In preparing to use the conventional genetic algorithm operating on fixed-length character strings to solve a problem, the user must 1. determine the representation scheme, Ann Arbor: The University of Michigan Press