  Data from high-energy physics (HEP) experiments are collected with
significant financial and human effort and are in many cases unique. At the
same time, HEP has no coherent strategy for data preservation and re-use, and
many important and complex data sets are simply lost. In a period of a few
years, several important and unique experimental programs will come to an end,
including those at HERA, the b-factories and at the Tevatron. An
inter-experimental study group on HEP data preservation and long-term analysis
(DPHEP) was formed and a series of workshops were held to investigate this
issue in a systematic way. The physics case for data preservation and the
preservation models established by the group are presented, as well as a
description of the transverse global projects and strategies already in place.
