title: Who's afraid of file format obsolescence? Evaluating file format endangerment levels and factors for the creation of a file format endangerment index
abstract: Much digital preservation research has been built on the assumption that file format obsolescence poses a great risk to the continued access of digital content. In an endeavor to address this risk, a number of researchers created lists of factors that could be used to assess risks associated with digital file formats. This research examines these assumptions about file format obsolescence and file format evaluation factors with the aim of creating a simplified file format endangerment index. This study examines file format risk under a new lens of file format endangerment, or the possibility that information stored in a particular file format will not be interpretable or renderable in human accessible means within a certain timeframe. Using the Delphi method in two separate studies, this exploratory research collected expert opinion on file format endangerment levels of 50 test file formats; and collected expert opinion on relevance of 21 factors as causes of file format endangerment. Experts expressed the belief that generally, digital information encoded in the rated file formats will be accessible for 20 years or more. This indicates that file format experts believe that there is not a great deal of short-term risk associated with encoding information in the rated file formats, though this does not preclude continued engagement with preservation activities for these and other file formats. Furthermore, the findings show that only three of the dozens of file format evaluation factors discussed in the literature exceeded an emergent threshold level as causes of file format endangerment: 'rendering software available', 'specifications available', and 'community/3rd party support.' These factors are ideal candidates for use in a file format endangerment index. Such an index allows only for the inclusion of formative indicators, or factors that indicate a cause of file format endangerment. The three factors shown to be the most relevant as causal indicators of file format endangerment, 'rendering software available', 'specifications available', and 'community/3rd party support' are the best candidate indicators to build into the index. The intention is to construct and validate an index using these three candidate factors as part of a future research agenda.