Overview

The FIGIS project has been an early exponent of the AG standards, participating in their development and incorporating them within its own metadata structures. The AGS draft 1.1 contains a number of new elements required by the FIGIS project, thus lessening FIGIS' need to extend AGS with its own elements.

Status

FIGIS has created an XML DTD expression of the current AGS standard and is using it within its XML documents.

Issues:

Extensions: There are several elements needed by FIGIS that are not found in the AG standard. FIGIS has therefore extended the standard in several places. Below is an image of the FIGIS Biblio_Entry element showing its element refinements. The blue elements are FIGIS-specific elements that were added at the request of our editors. The yellow elements are elements found in the Dublin Core element set that are not included in the AG standard.

The FIGIS extensions are few. It would be interesting to discuss whether these additions may be included within the framework of AGS, or whether the AGS authors have suggestions on ways for FIGIS to encode the data in a different way using the existing AGS structure. Particularly in the case of dc:Source FIGIS recommends the addition of this element to AGS as it is one of the Dublin Core main elements and fulfills a function not handled by any other DC or AG elements, namely indicating the source from which a present source is derived.

Other Issues:

Many editors have trouble with dc:Date. The encoding standard of YYYYMMDD is logical (from lesser to greater precision) but editors are used to the european notation of DDMMYYYY or the north american of MMDDYYYY. There is a real danger that information may be encoded incorrectly. In the past, FIGIS used explicit attributes for day, month and year so that the element was encoded like this: <DATE year="2002" month="09" day="19"/>. FIGIS may consider returning to this model by extending the dc:Date attributes.

Notes on FIGIS use of Metadata:

Below are diagrams of the other FIGIS elements used to contain DC and AGS metadata. It may be helpful to examine how FIGIS uses these metadata elements within its overall design.

All FIGIS documents begin with the DataEntry container identifying the document encoder:

To see an example of an XML document containing the DataEntry element click here.

This is followed by the top-level container ObjectSource used to contain metadata about the FIGIS document in which it is found (and the objects within the document):

ObjectSource has two main branches, Owner and CoverPage.

To see an example of an XML document containing the CoverPage element click here.

It is important to note that all the metadata containers we have been looking at so far contain information directly about the document itself. Within the FIGIS structure there are also several elements that allow users to encode metadata found in a source document used in part or in whole to create the FIGIS document. In effect, going down one level. There is the Bibliography container element (used as is a traditional print bibliography) found at the end of a FIGIS document. It contains formatted text and one or more BiblioEntry elements:

There is also the Literature container used as a suggested or additional reading container (as often found at the end of a traditional print publication):

To see an example of an XML document containing the Bibliography element (identical but in name to that of the Literature element, click here.

And then there is the looser concept of Sources, a bibliographic container that refers to the information found at or below its level in the document tree. It can be inserted almost anywhere in a document and is typically used when a section of a document is updated and so requires updated metadata in one area only:

To see an example of an XML document containing the Sources element (again, identical but in name to that of the Literature and Bibliographyelements, click here.

Lastly, to deal with linking between references, (for example a short author/page reference found in the middle of a book that refers to the full bibliographic citation found at the end) there is BiblioEntryLink:

Clearly, these high-level containers used by FIGIS do not fall within the AGS scheme, but use AGS elements to hold their metadata. These real-world examples of how FIGIS incorporates the AGS elements may help promote the standard. In addition, AGS may consider adopting or promoting some or all of the FIGIS structures (e.g. Bibliography and BiblioEntry) for use by others both within and without the FAO. The structures used by FIGIS reflect a long process of design and real-world testing, experience that may benefit new users.

Conclusion

The AG standard is an important step in harmonising the indexing of FAO and other agricultural data. FIGIS will continue using the standard to encode its document metadata. It is hoped that a stable and mature standard is not far off as the time needed to update and modify tagged documents to meet evolving standards can be great.