Preservation ensures access to digital content over time (see
ALA definition for digital preservation). CESSDA archives
provide access to social science data and ensure the usability
of the data during its life cycle. Good data management from the
beginning of the data life cycle reduces the preservation costs.
Repairing records with low quality metadata is much more
expensive than creating metadata in the pre-archiving phase. The
costs of keeping research data safe are explored further in the
Report on the 2008 Annual Conference of the Alliance for
Permanent Access. Most CESSDA archives have implemented a
preservation strategy based on open and standardised file
formats, data migration and media refreshment. Preservation
decisions are usually made within the context of the overall
collections development policy of the archive, balancing the
constraints of cost, scholarly and historical value, and user
accessibility. In some archives, a strategy has been adopted to
store data on at least two and often three d