In selecting metadata schemas or standards to use for the Knowledge for All citation database, it is important to consider the information or metadata elements needed for different types of content in the database (outlined in Metadata Elements) standards used by sources that metadata will be harvested from (noted in Metadata Sources), standards used by institutions that will be harvesting data from Knowledge for All, and standards used by other tools that may be used in the data harvesting, creation, and editing process. There are many different metadata schemas for bibliographic description in use by different institutions and standards are always changing, so interoperability is the key as opposed to conforming strictly to one particular standard. This process will inevitably evolve as workflows are developed, data harvesting methods are determined, and technical infrastructure is designed. Here are some initial recommendations.  In addition to considering standards and schemas used by other repositories, I reviewed research on metadata standards used in digital libraries and specifically metadata standards used for electronic journal article data.  Initial research by Vanessa Black and Rebecca Prescott was also utilized.

There is no standard metadata schema for journal article records. The most common bibliographic metadata schema for digital materials in general is Dublin Core. Although Dublin Core is widely recognized as insufficient for describing journal article metadata due to its simplicity and limited number of elements, many institutions still use Dublin Core because of its interoperability and wide use. The Dublin Core Metadata Initiative Citation Working Group analyzed this issue and published Guidelines for Encoding Bibliographic Citation Information in Dublin Core Metadata. Many institutions which have chosen to use Dublin Core for journal articles have also documented how they adapted it to meet their needs (see references). As stated by Apps and MacIntyre (2002), “Dublin Core should remain a ‘core’ set of metadata elements, with domain-specific metadata recorded according to more complex standards, whether extensions to Dublin Core or separate standards.” In addition, Dublin Core is the metadata standard required by the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH), which itself is quickly becoming the standard through which institutions make their metadata available. It is recommended that Knowledge for All use a form of Dublin Core or incorporate Dublin Core elements into its metadata schema. 

Metadata Object Description Schema (MODS) is another important metadata schema for descriptive bibliographic data because of its wide use and compatibility with MARC, the data format in which libraries exchange bibliographic records. Like Dublin Core, it is built on an XML foundation. Although not widely used for journal article metadata, MODS is a more complex and specific schema than Dublin Core and can be used in conjunction with Dublin Core for more specificity and granularity.

The Open Knowledge Foundation's Open Bibliographic Data project has developed BibJSON, a simple description of how to represent bibliographic metadata in the JSON format, and is using this schema for its open bibliographic data.  This option should be examined further.

Metadata Encoding and Transmission Standard (METS) is a standard for encoding descriptive, administrative, and structural metadata that could be used to bundle multiple metadata sets together.

Scholar name authority files should follow the Metadata Authority Description Standard (MADS) and Friend of a Friend (FOAF) ontology so as to be compatible with MARC and easily used by other systems.

References and resources

Allinson, Julie, Pete Johnston, and Andy Powell. “A Dublin Core Application Profile for Scholarly Works.” Ariadne 50 (January 2007). Retrieved 8 April 2011 from http://www.ariadne.ac.uk/issue50/allinson-et-al/.

Apps, Ann and Ross MacIntyre. “Dublin Core Metadata for Electronic Journals.” Lecture Notes in Computer Science 1923 (2000): 93-102. Retrieved 31 March 2011 from http://eprints.rclis.org/bitstream/10760/12183/1/appsmacecdl2000_full.html

Apps, Ann and Ross MacIntyre. “zetoc: a Dublin Core Based Current Awareness Service.” Journal of Digital Information 2 (2002). Retrieved 31 March 2011 from http://journals.tdl.org/jodi/article/viewArticle/39

Dappert, Angela and Markus Enders. “Using METS, PREMIS and MODS for Archiving eJournals.” D-Lib Magazine 14.9/10 (September/October 2008). Retrieved 4 April 2011 from http://www.dlib.org/dlib/september08/dappert/09dappert.html

Directory of Open Access Journals' XML schema for journal articles

Dublin Core Metadata Initiative Bibliography