The maximum size of bulge loops or insertions and deletions is three bases. MINMATCH - MINMATCH is the minimum number of exact matches in a homology or symmetry that must be met before SEQ will print out the match. If set to 10 for example, only homologies that have at least 10 nucleotides matched will be reported. MINMATCH effects the number of comparisons made near the ends of sequences. If set to 10, for insiance, the first 10 nucleotides of one sequence will not be paired with the last ten of the other. PERCENTMATCH - PERCENTMATCH is the minimum ratio of matched nucleotides to total nucleotides in a homology or a symmetry in order for that match to be printed. However, it has an additional consequence due to the fact that the SEQ searching algorithm proceeds unidirectionally along a sequence. The homologies that are generated by sequence comparisons can never be less matched than PERCENTMATCH at any point in the homology. This means that the homologies that are printed will start off well paired and will then degenerate.

The Key idea is to represent explicitly and separately: a A. The limitations of MYCIN for application to teaching domain-independent diagnostic strategy in the form of meta-rules,

Expert Systems constitute a subclass of Al reasoning programs which are distinguished by criteria of usefulness and understandability as well as performance. In this paper these criteria are discussed, the state of the art of so-called "Level-1" Expert Systems is assessed, and the research topics necessary for moving to Level-2 systems are reviewed.

To be presented at the Eighteenth Annual Meeting of the Drug Information Association, Kansas City, Missouri, June 16, 1982. Edward H. Shortliffe, MD, PhD Assistant Professor of Medicine and Computer Science Heuristic Programming Project Department of Medicine Stanford University School of Medicine Stanford, California 94305 To be presented at the Eighteenth Annual Meeting of the Drug Information Association Kansas City, Missouri 16 June 1982 ABSTRACT The trend towards increased use of computer-based symbolic reasoning techniques for clinical decision making programs stems from the dual goals of improving the performance and increasing the acceptance of such systems. This talk will summarize the design considerations that have encouraged some recent investigators to turn to artificial intelligence techniques when'bJllding consultation systems. Some of the recent experimental consultation systems are less concerned with reaching correct diagnoses than with advising physicians un optimal treatment strategies for patients with known serious ..',Iscases. Examples for discussion will be drawn from (1) the MYCIN system, a consultation program to advise physicians on the selection of antimicrobials for patients with bacteremia or meningitis, and (2) ONCOCIN, a recently developed program for advising oncologists on therapy adjustment in the manarement of patients enrolled in cancer chemotherapy protocols.

The educational needs of these individuals are very different from those of the future medical compu'ing researcher.

It is frequently observed that medicine.

This wolk was supported in parts by the Defense Advanced Rz-search Projects under ARPA contract no. MDA 903-77-C-0322 and National Institutes of He...Ith grant no.

The UNIT Package Is a frame-structured, hierarchically-organized knowledge representation and acquisition system. It was originally developed for the MOLGEN project at Stanford University [Stefik, 19701 [Friedland, 19791 [Stet ik, 19801 Tho package contains a sot of data structures and access functions for program manipulation of those structures. In addition, it contains a sophisticated Interactive editor, called UE. This editor enables a domain export (not necessarily a computer specialist) to construct a knowledge baso through direct interaction with tho computer; that is, tho transfer of expertise from domain export to machine flood not be mediated by a computer specialist. This document is intended to servo several purposes and parts of It can be Ignored by some readers.

We expect that the percentage of DNA which codes for heuristics rather than proteins would increase with the complexity and sophistication of the organism. Man should have more heuristics than chickens, which should have more than E. coll. This isn't because we're "better", just because our DNA program is longer and more involved; if our ability to adapt is to be anywhere near as good as bacteria's, we must compensate for our unwieldy program size and generation time by employing poweful judgmental rules, heuristics which put each generation to maximum use.

So. up to a point, does (achi.v. ( Note that propositions stashed in theories other than the currently writeable one are not affected. It is the user's responsibility to ensure that there are never two or more theories active which use different representations for the same proposition.)