EpiData is a software package which allows data definitions, data documentation , data entry and analysis based on the project principles in Dublin Core Elements and datadocumentation principles at project and variable level as implemented in DDI standards. Including tools for double data verification and quality assurance measures (restriction of values, labels, comparison of fields, structured jumps, related data files) . Encryption principles and user logging is an option. Version control is implemented as an automatic counter and with appropriate date registration of changes in structure and data contents. Backup procedures at project level ensures possibility to "roll back" to previous versions.
Following definition, entry and verification of data export can be made to a verified DDI-3.1 XML structure. The DDI export has been verified, funded by and implemented in collaboration with the Danish National Archives (www.sa.dk).