Knowledge Systems Bruce Porter Department of Computer Sciences The University of Texas at Austin

… but it can only solve math problems. Imagine a similar tool for chemistry and other domains. UT Knowledge System toolkit enables just that. Spreadsheet is a tremendous tool…

Knowledge Systems  Knowledge Systems use formal representations of knowledge to answer unanticipated questions with coherent explanations.  Knowledge System = Knowledge Base + Q/A + Explanation generator + Knowledge Acquisition tools

Advances over expert systems Advances over expert systems  Coverage of domain, not domain  task  Various modes of reasoning, well integrated  Domain-level explanation  Rapid construction

Victory in Project Halo  Outscored all other competitors and passed Advanced Placement (AP) chemistry exam  Long-term: build a Knowledge System encompassing much of the world’s scientific knowledge.  Short-term: assess current technologies.  Use a portion of the AP chemistry exam as a metric.

Example questions  The spectator ions in the reaction of barium nitrate with sodium sulfate are what? (choices)  Although nitric acid and phosphoric acid have very different properties as pure substances, their aqueous solutions possess many common properties. List some general properties of these solutions and explain their common behavior in terms of the species present.  Explain why a solution of HClO 4 and NaClO 4 cannot act as a buffer solution.  Sodium azide is used in air bags to rapidly produce gas to inflate the bag. The products of the decomposition reaction are what? (choices) Questions were manually encoded in our formal language.

An example explanation  What are the products of the given decomposition reaction? By definition, oxidation-reduction reactions occur when electrons are transferred from the atom that is oxidized to the atom that is reduced. We need to look for changes in the oxidation states of the elements in the reaction.By definition, oxidation-reduction reactions occur when electrons are transferred from the atom that is oxidized to the atom that is reduced. We need to look for changes in the oxidation states of the elements in the reaction.  In the reactants, the oxidation state(s) of the element Na is/are (1). In the product, the oxidation state(s) is/are (0).  Therefore, the reaction causes a change in oxidation state. Therefore, this is an oxidation reduction reaction. By definition, a Binary Ionic-Compound Decomposition Reaction occurs when a binary ionic compound is heated.By definition, a Binary Ionic-Compound Decomposition Reaction occurs when a binary ionic compound is heated. Therefore, this reaction is a Binary-Ionic Compound Decomposition reaction. In general, a Binary Ionic-Compound Decomposition Reaction converts a binary ionic-compound into basic elements.In general, a Binary Ionic-Compound Decomposition Reaction converts a binary ionic-compound into basic elements. In this reaction, NaN 3 reacts to produce Na and N 2.  The products of the decomposition reaction are: (d) Sodium and nitrogen-g.

UT software toolkit  KM: System for Knowledge Representation and Automated Reasoning  Component Library: building blocks for quickly assembling knowledge bases  AURA: Knowledge Acquisition tool Does not require software programmer or knowledge engineer to implement

Potential applications  Chemistry  Biology  Education  Medicine  Engineering  Business applications  Many other domains