Information systems have been rapidly evolving from monolithic/ transactional to network/service based systems. The issue of data quality is becoming increasingly important, since information in new information systems is ubiquitous, diverse, uncontrolled. In the paper we examine data quality from the point of view of dimensions and methodologies proposed for data quality measurement and improvement. Dimensions and methodologies are examined in their relationship with the different types of data, from structured to unstructured, the evolution of information systems, and the diverse application areas.