Authenticity - Advanced Digital Preservation - page 229

be a useful guide to a data user wishing to determine the authenticity of these
data files.
In order for the Authenticity Protocol designer to model what PDI needs to be
captured and also for a future data user to establish if all the evidence is available,
the Authenticity Protocol should include a qualifying statement of intent, decided
as the first step and forming part of the Authenticity Recommendations. For each
AP there also needs to be Authenticity Steps stating clearly and unambiguously the
criteria that the intended captured evidence must support. Only when this is decided
can the scope of the capture be decided and the correct PDI necessary to support this
claim be determined. To design the WDC Authenticity Protocols, it is important to
identify the major event types that occur between the data arriving and its final
storage. These event types map to the APs.
If the WDC set the initial criteria “to record PDI necessary to verify the authen-
ticity and quality of received data files for long term archival within the WDC” then
the appropriate event types that occur in the system up to and including the point of
long term storage within the archival ingestion system can be identified. In this sce-
nario there are three event types which can occur between ingestion and archival of
the incoming Ionosonde data files. The occurrence of these event types will trigger
the execution of the following APs:

• Ingestion of raw data files in varying formats

• Transformation of received data files into IIWG format

• Final validation and archival of IIWG file within WDC

Each AP should have an Authenticity Step stating the criteria against which these
steps are measured, for example:

1. Ingestion of raw data files in varying formats - “In order for this digital data
to be accepted as Ionosonde data of sufficient quality the reliability of its source
must be verified and recorded by a WDC accredited archivist”
2. Transformation of received data files into IIWG format - “For the received data
file to be deemed as sufficient quality to support data analysis it must have been
successfully transformed into standard IIWG data format, the use of processing
software must be recorded”
3. Final validation and archival of IIWG file within WDC - “Successful validation
of the IIWG structure and syntax must be achieved and recorded before long
term archival can take place”

At this point it is possible to identify the necessary steps for each protocol, these are
shown in Table 13.1 .
The Authenticity Steps for each protocol can now be completed with the specific
PDI fields necessary for modelling the capture of the appropriate evidence. The
complete list of PDI fields is considerable and is not included here.
The completed steps with PDI fields are then encoded into the XML schema and
imported into the tool. The authenticity steps can then be followed through the tool
with all captured information being used to create the digest for export.