The difficulty and expense of preserving digital information is a potential impediment
to digital library development. Preservation of traditional materials became more successful and
systematic after libraries and archives integrated preservation into overall planning and resource
allocation. Digital preservation is largely experimental and replete with the risks associated with
untested methods. Digital preservation strategies are shaped by the needs and constraints of repositories
with little consideration for the requirements of current and future users of digital scholarly
resources. This article discusses the present state of digital preservation, articulates requirements of
both users and custodians, and suggests research needs in storage media, migration, conversion, and
overall management strategies. Additional research in these areas would help developers of digital
libraries and other institutions with preservation responsibilities to integrate long-term preservation
into program planning, administration, system architectures, and resource allocation.