|Authors:||Balder ten Cate (UC Santa Cruz)
Phokion G. Kolaitis (UC Santa Cruz and IBM Research - Almaden)
Wang-Chiew Tan (UC Santa Cruz)
|Abstract:||A fundamental task in data integration and data exchange is the design of schema mappings, that is, high-level declarative specifications of the relationship between two database schemas. Several research prototypes and commercial systems have been developed to facilitate schema-mapping design; a common characteristic of these systems is that they produce a schema mapping based on attribute correspondences across schemas solicited from the user via a visual interface. This methodology, however, suffers from certain shortcomings. In the past few years, a fundamentally different methodology to designing and understanding schema mappings has emerged. This new methodology is based on the systematic use of data examples to derive, illustrate, and refine schema mappings.
Example-driven schema-mapping design is currently an active area of research in which several different approaches towards using data examples in schema-mapping design have been explored. After a brief overview of the earlier methodology, this tutorial will provide a comprehensive overview of the different ways in which data examples can be used in schema-mapping design. In particular, it will cover the basic concepts, technical results, and prototype systems that have been developed in the past few years, as well as open problems and directions for further research in this area.
|Authors:||Nurit Gal-Oz (Ben-Gurion University and Sapir Academic College, Israel)
Ehud Gudes (Ben-Gurion University, Israel)
Trust and Reputation have become key enablers of positive interaction experiences on the Web. These systems accumulate information regarding activities of people or peers in general, to infer their reputation in some context or within a virtual community. Reputation information improves the quality of interactions between peers and reduces the effect of fraudulent members. In this tutorial we motivate the use of trust and reputation systems and survey some of the important models introduced in the past decade. Among these models, we present our work on the knot model, which deals with communities of strangers. Special attention is given to the way existing models tackle attempts to attack reputation systems. In a dynamic world, a person or a service may be a member of multiple communities and valuable information can be gained by sharing reputation of members among communities. In the second part of the tutorial, we present the CCR model for sharing reputation across virtual communities and address major privacy concerns related to it. In the third part of our talk, we discuss the use of reputation systems in other contexts, such as domain reputation for fighting malware, and outline our research directions on this subject.
|Authors:||Paolo Missier (Newcastle University, UK)
Khalid Belhajjame (University of Manchester, UK)
James Cheney (University of Edinburgh, UK)
|Abstract:||Provenance, a form of structured metadata designed to record the origin or source of information, can be instrumental in deciding whether information is to be trusted, how it can be integrated with other diverse information sources, and how to establish attribution of information to authors throughout its history. The PROV set of specifications, produced by the World Wide Web Consortium (W3C), is designed to promote the publication of provenance information on the Web, and offers a basis for interoperability across diverse provenance management systems. The PROV provenance model is deliberately generic and domain-agnostic, but extension mechanisms are available and can be exploited for modelling specific domains. This tutorial provides an account of these specifications. Starting from intuitive and informal examples that present idiomatic provenance patterns, it progressively introduces the relational model of provenance along with the constraints model for validation of provenance documents, and concludes with example applications that show the extension points in use.|