  All sciences, including astronomy, are now entering the era of information
abundance. The exponentially increasing volume and complexity of modern data
sets promises to transform the scientific practice, but also poses a number of
common technological challenges. The Virtual Observatory concept is the
astronomical community's response to these challenges: it aims to harness the
progress in information technology in the service of astronomy, and at the same
time provide a valuable testbed for information technology and applied computer
science. Challenges broadly fall into two categories: data handling (or "data
farming"), including issues such as archives, intelligent storage, databases,
interoperability, fast networks, etc., and data mining, data understanding, and
knowledge discovery, which include issues such as automated clustering and
classification, multivariate correlation searches, pattern recognition,
visualization in highly hyperdimensional parameter spaces, etc., as well as
various applications of machine learning in these contexts. Such techniques are
forming a methodological foundation for science with massive and complex data
sets in general, and are likely to have a much broather impact on the modern
society, commerce, information economy, security, etc. There is a powerful
emerging synergy between the computationally enabled science and the
science-driven computing, which will drive the progress in science,
scholarship, and many other venues in the 21st century.
