Knowledge Sharing and Arden Syntax (Introduction to Medical Informatics) (http://www.cpmc.columbia.edu/edu/textbook) LAST REVIEWED: 6 November 1996 rationale the medical domain is huge no one group will cover it all therefore will need to share knowledge will need to link knowledge together types of knowledge sharing knowledge base reuse - taking the knowledge encoded in a KB and using it for another purpose (within an institution or between organizations) hypokalemia and digoxin cause arrhythmia - want to generate several MLMs from this one fact, want to reuse the definition of hypokalemia separate domain knowledge (declarative facts) from problem solving knowledge (how to use the facts) reuse would allow the same hospital to use a KBS 10 different ways (avoid rewritting the KBS 10 different ways) knowledge base transfer - use of a KBS in a different location, by different users, ... for the same purpose for which it was intended transfer would allow 10000 hospitals to use the same KBS obstacles to sharing different knowledge representations belief network KL-ONE frames production rules neural network nodes disease profiles MLMs local prior probabilities local medical practice not-invented-here syndrome local vocabulary database schema liability royalties multicenter maintenance language differences validation/verification/evaluation licensing: practice outside of originating jurisdiction distributing the knowledge examples of sharing efforts scientific publications this is how knowledge is shared today drug-drug interaction knowledge bases successful distribution by several vendors HELP purchase a monolithic system that contains a KBS QMR QMR conversion to QMR-DT comparison with Iliad multi-center creation of QMR KB Iliad translation to French, German Knowledge Interchange Format (KIF) = Interlingua single rep. that all KBs can be translated to one to many instead of many to many based on predicate calculus in LISP lowest common denominator Knowledge Representation System Specification translate only represenatations within a family eg, KL-ONE frame representation KQML interface KBSs using query language (like SQL) Arden Syntax (see below) Arden Syntax Arden Homestead retreat - leaders from 20 MI departments around the world to discuss sharing divided knowledge into three types modular independent (MLMs) modular dependent (QMR) interwoven (causal network) begin with sharing modular independent KBs can share a single rule and still be useful can test the KBS rule by rule real systems (vs theoretical) use this paradigm each MLM contains enough logic to make a single medical decision proposed an early version of the Arden Syntax based upon earlier proven systems HELP and RMRS later joined the ASTM standards organization consensus group, allows industry to participate legal protection (constraint of trade) KB is composed of Medical Logic Modules (MLMs) ASCII file of slots grouped into 3 categories maintenance category concerned with maintenance, version control, ... title - allow institution-specific name filename version - track MLM versions institution author specialist - who approved the MLM for real use date - track MLM versions validation - what use is it approved for library category text, links to knowledge sources purpose explanation keywords -KB searches citations links knowledge category actual medical content of the MLM procedural representation type data - mapping priority evoke - context logic - criteria action urgency data slot separate institution-specific mappings from logic queries, messages (storage), events, ... queries based on study of real clinical databases very little in common among real databases therefore queries are made of 4 components variable = MLM's name for an entity aggregation operator (eg, last, min) time constraints curly expression = everything else institution-specific syntax experience with sharing MLMs most of MLM is dedicated to KBS-DB link most of performance is due to KBS-DB link vocabulary causes largest number of necessary changes schema causes the most extensive changes some of logic must be changed, too (logic statements used to filter *content* of local data, as opposed to adjusting for its name [vocabulary] or location [schema]) related reading: George Hripcsak, Peter Ludemann, T. Allan Pryor, Ove B. Wigertz, Paul D. Clayton. Rationale for the Arden Syntax. Computers and Biomedical Research 1994;27:291- 324.