—Data quality assessment is a challenging but neces- sary task to ensure that business decisions that are derived from data can be trusted. A number of data quality metrics have been developed to measure dimensions like accuracy, completeness, and timeliness. The tool QuaIIe (developed as part of our previous research) facilitates the calculation of different data quality metrics on both, schema- and data-level, and for heterogeneous information systems. However, to gain meaningful results from the automatically calculated metrics, it is key that humans understand the results of such metrics. This understanding is specifically important when contextual information needs to be considered, which is not encoded in the data. In this paper, we present a visualization approach to enable human-centered data quality assessment across multiple dimensions and arbitrary complex data sources. The approach has been implemented as graphical user interface in QuaIIe.
Schema and data integration have been a challenge for more than 40 years. While data warehouse technologies are quite a success story, there is still a lack of information integration methods, especially if the data sources are based on different data models or do not have a schema. Enterprise Information Integration has to deal with heterogeneous data sources and requires up-to-date high-quality information to provide a reliable basis for analysis and decision making. The paper proposes virtual integration using the Typed Graph Model to support schema mediation. The integration process first converts the structure of each source into a typed graph schema, which is then matched to the mediated schema. Mapping rules define transformations between the schemata to reconcile semantics. The mapping can be visually validated by experts. It provides indicators and rules to achieve a consistent schema mapping, which leads to high data integrity and quality.
—Code generators often have something mystical about them. Especially undergraduate students, who can still remember their first steps in programming, become in awe when they hear the term ”Software Generator”. The paper is an attempt to take this awe away from the students and to show them, by means of a very simple example implementation with well-known tools and technologies, that software generators are not witches’ work, but a powerful, but easily understandable tool to support the software development process.
