Over recent years significant progress has been made in understanding the issues involved in preserving complex materials and environments. Recent work undertaken in the Planets and KEEP projects has shown that the problems involved in preserving materials and environments, while substantial, are by no means intractable.


In order to continue to make progress it is important to engage and energise the wider DP community. An important aspect of this involves articulating the state of the art by synthesising the research results so far achieved in a number of independent projects, and clearly signposting areas where work remains to be done.


These were the principal objectives which POCOS addressed. It is essential to note that the nature of complex digital objects is such that there are multiple layers of difficulty encountered when attempting to analyse them. These layers could be superficially likened to Cantor’s “levels of infinity” in terms of mapping out the size of the problem space, and this needs careful treatment in the analysis of the topic as well as in the symposia.


The first “level of infinity” is that of detail:


However, significant properties under migration encompasses not only the “level of infinity” concerning detail, but also another one to do with scale:


One new area of research introduced by POCOS was that of Computer History – involving a community that has not been widely engaged in digital preservation / emulation and can contribute much to this project. Also, modelling large complex data has been successfully tackled by computer scientists working in the business community using data warehousing, but this knowledge has been slow to transfer to other domains. The POCOS consortium included members belonging to both the computer history and the data warehousing fields, who brought clarity and relevance to the debate resulting from years of synthesising, extending and applying the results of research springing from cross-fertilisation between these domains. This formed the basis for undertaking the main project objectives: Identifying the relevant national and international initiatives, plus the main protagonists in the area.