Trustworthy Semantic Webs Dr. Bhavani Thuraisingham The University of Texas at Dallas Lecture #4 Vision for Semantic Web

Outline l Today’s Web l From web to semantic web l Applications and Technologies l Layered Approach l Reference: Chapter 1 of the book A semantic web primer: Antoniou and van Harmlen

Today’s Web l High recall, low precision: Too many web pages resulting in searches, many not relevant l Sometimes low recall l Results sensitive to vocabulary: Different words even if they mean the same thing do not results in same web pages l Results are single web pages not linked web pages

From Today’s Web to the Semantic Web l Machine understandable web pages l Activities on the web such as searching with little or no human intervention l Technologies for knowledge management, e-commerce, interoperability] l Solutions to the problems faced by today’s web - Retrieving appropriate web pages, sensitive to vocabulary etc. - Semantic web applications including

Knowledge Management l Corporation Need - Searching, extracting and maintaining information, uncovering hidden dependencies, viewing information l Semantic web for knowledge management - Organizing knowledge, automated tools for maintaining knowledge, question answering, querying multiple documents, controlling access to documents

Business to Consumer E-Commerce l Users shopping on the web; wrapper technology is used to extract information about user preferences etc. and display the products to the user l Use of semantic web: Develop software agents that can interpret privacy requirements, pricing and product information and display timely and correct information to the use; also provides information about the reputation of shops l Future: negotiation among the behalf of the user

Business to Business E-Commerce l Organizations work together and carrying out transactions such as collaborating on a product, supply chains etc. With today’s web lack of standards for data exchange l Use of semantic web: XML is a big improvement, but need to agree on vocabulary. Future will be the use of ontologies to agree on meanings and interpretations

Personal Agents l John is a president of a company. He needs to have a surgery for a serious but not a critical illness. With current web he has to check each web page for relevant information, make decisions depending on the information provided l With the semantic web, the agent will retrieve all the relevant information, synthesize the information, ask John if needed, and then present the various options to John and also makes recommendations

Semantic Web Technologies l Explicit metadata - XML, RDF, etc. l Ontologies l Logic l Agents

Explicit metadata l Metadata is data about data l Need metadata to be explicitly specified so that different groups and organizations will know what is on the web l Using metadata, one can then carry out various activities such as searching, integration and executing actions l Metadata specification languages include XML and RDF

Ontologies l Explicit and formal specification of conceptualization describes a domain of discourse l Consists of concepts and prelateships between them l Web searches can exploit ontologies to facilitate the search process l Ontology languages include XML, RDF, OWL

Logic l Logic can be used to specify facts as well as rules l New facts and derived from existing facts based on the inference rules l Descriptive Logic is the type of logic that has been developed for semantic web applications

Agents l Agents are essentially processes that have evolved from object-oriented programming; agent is an active objects l Agents will use metadata to find resources on the web; ontologies will be used to interpret statements; logic will be used for drawing conclusions l Agents will not completely replace humans; but will make the tasks of the humans much easier.

Semantic Web vs Artificial Intelligence l Goal of Artificial Intelligence is to build an intelligent agent exhibiting human-level intelligence l Goal of the semantic web is to assist the humans in their day to day online activities

Layered Approach: Tim Berners Lee’s Vision