Chapter 4: Metadata Magic 101 One of the paths not fully explored in personal media metadata is to leverage social activity as a metadata resource: the sharing, discussions, and popularity infor- mation already available in many services. Social activity around personal media is important to the end-users and formalizing it into metadata would enable new kinds of approaches for solving the personal media management problem. Dr. Risto Sarvas Researcher Helsinki Institute for Information Technology HIIT, Finland (Dr. Risto Sarvas’ work has focused on designing user-centric metadata for digital snapshot photography. His current research goal is to bridge the gap between photography studies in technical, cultural, and social sciences.) 4.6.1 MARC Data about data has existed practically for as long as data has existed. The history of metadata can be tracked back to the days of the fi rst libraries, where librarians catalogued the books in the collection, making it signifi cantly easier to locate a desired book. Obviously, they were not thinking in terms of metadata, but rather indexes or catalogues. Not surprisingly, then, one of the fi rst metadata formats is MARC 27 (Machine Readable Catalogue), a format devised to transfer catalogue records between library systems and based on age-old cataloguing cards used in libraries (Dovey 2000). Several variations of MARC exist, such as UKMARC (developed and promoted by British Library), MARC21 (maintained by the Library of Congress in the US), and UNIMARC. Typically, one MARC record consists of a number of fi elds, labelled from 0 to 999. Each fi eld has a number of indicators that defi ne its semantics, and a number of subfi elds. For instance, fi eld 245 indicates the title, and the subfi elds indicate any additional information related to the title, such as additional title, statement of responsibility, and so forth (Dovey 2000). MARC records are stored in binary format, even though they can be also rendered textually, which allows them to be edited directly 27 Please see the following Web link for detailed information on MARC: http://www. loc.gov/marc