Workbook on Digital Private Papers > Arranging and cataloguing digital and hybrid archives > EAD templates for a personal archive
EAD templates for a personal archive
Linking from the catalogue to digital objects: at what level should this be done?
The ability to link directly from an EAD catalogue to the digital archive material it describes was identified as desirable by the Paradigm Academic Advisory Board. The survey of the Archives Hub users suggested that linking directly to born-digital records was a slightly lower priority for them than having access to item-level descriptions, but it was still considered of some importance. The 2004 Linking Arms survey co-ordinated by the National Council on Archives (which reflects the needs of a slightly different audience, including a high proportion of family and local historians) found that 55% of those who responded expressed a wish to access and/or download content of documents (such as digital images), rather than just catalogue descriptions.
It will only be possible for remote users to link directly to born-digital records in those cases where the digital material is either already in the public domain or copyright permission has been obtained from the rights holder, and any other legislative restrictions have expired. It may also be possible to provide direct access from catalogue to digital archive on a standalone PC in a searchroom if copyright is the only restriction which applies (see Chapter 09 Legal issues for more detail on IPR and access restrictions).
EAD allows for linking directly from catalogue entries to born-digital archive material held outside the catalogue, by means of two elements or tags: <dao> (Digital Archival Object) and <daogrp> (Digital Archival Object Group). To date, these tags have mostly been used to link to digitised images of the material described in the catalogue, but they are also explicitly recommended (in the Research Libraries Group (RLG) Best Practice Guidelines for Archival Description) for creating links to born-digital objects if they are the focus of the finding aid.
Linking to an individual digital object from an item level description should be relatively straightforward, and where item-level descriptions have been created, it is recommended that the link be made from that level. RLG recommend using <daogrp> rather than <dao>, both for consistency throughout a finding aid and because it facilitates linking to more than one digital representation. However, it seems most appropriate to use <dao> if the repository intends to use METS files for disseminating objects; the link could be made to a METS file, which contains links to different representations of the item and further metadata about it. This would reduce the need to update the EAD catalogue as files are migrated to new formats.
The <dao> tag is probably most appropriately placed as the last sub-element within the <did> tag. The <did> is a required wrapper element that bundles together elements identifying core information about the described item, such as reference code, title, date and physical description of the object. If <dao> is placed in this context, the archivist will not have to supply the additional <daodesc> element, which is designed to contain information about the contents, usage or source of the digital archival object when the information in other tags is insufficient to identify the object.
<dao> must contain various attributes in order to: connect the finding aid to the location of the digital object (or DIP); determine how this link is made by the user; and determine how the DIP will be displayed, e.g.:
In this example, the linktype is simple (because only a single digital object is concerned), the link to the specified location of digital object is made at the request of the user rather than automatically, and the DIP will be displayed in a new window.
Whilst linking at item level is relatively straightforward, in many instances we may be unable to produce full item-level descriptions. Some solutions might be as follows:
- Provide a single link, using <dao>, from folder level. Users will be taken to the DIP for that folder; obviously a folder is not a document which can be viewed, so the DIP will only contain metadata about the folder. This will include structural metadata describing the relationships between this and other digital objects; users will therefore be able to identify all constituent files and navigate freely around them (all of which will have a level of descriptive and other metadata to aid understanding).
- Produce item-level catalogue entries with only a bare minimum of information (possibly automatically extracted) in each (reference code, title and date), with a <dao> link to the digital object.
- Catalogue to series level only, but embed a list of component digital items in the <scopecontent> at that level and make use of the <daogrp> tag to provide links to these items. <daogrp> is generally used to link to multiple digital representations of the same thing (e.g. a number of digitised images of the item described, each at a different resolution; or images of different pages from the same digitised manuscript); however, there seems no reason why it cannot be employed to link to a sequence of related items which make up a record series. The <daogrp> tag acts as a wrapper for a number of <daoloc> elements, pointing out the location of each object linked to; <daoloc> may contain a
element to supply a brief label for the digital object.
Using option 3, a co2 or co3 series (folder) level might look something like this:
Paradigm has no direct experience of linking digital archive material to an EAD catalogue in this way; ultimately the use of other attributes within <daoloc> should be determined locally, and guidance will be forthcoming in the light of practical experience in this area.
Of course, it would also be useful for users to link from a DIP to its associated catalogue description. This should be possible via the <dmdSec> section of the digital object's METS document; here the <mdRef> tag allows users to link to external descriptive metadata (in this case an EAD catalogue). By encoding a unique ID within the relevant <c> tag in the EAD catalogue (e.g. <c03 id="abc23" level="item">), the XPTR attribute in the METS <mdRef> can be used in conjunction with the ID value to identify and link to the relevant section of the EAD catalogue. This will be most effective where the decision is made to catalogue fully to item level in EAD, or when taking approach 2 outlined above. However, it will also be possible to link from the METS document for a single digital object to a collection- or series-level EAD description which includes the digital object as a component item.
