Sharing Knowledge: Scientific Communication - SSOAR

160 Judith Plümer
modification, the status of the document (preprint/article), the mimetype of the
original file, its language, source, URL and a rights statement.
The first extension to the standard Dublin Core element set that is specific
within the set was the use of „DC.subject.msc“ to store the MSC codes.
The encoding of the metadata is currently done via the HTML2.0 META tag.
However, the encoding of metadata in HTML 2.0 leads to some problems. For
example there is no grouping mechanism which says for example that this email
address belongs to that person’s name. That is the reason why we store only one
email address in the metadata files. HTML4.0 gives more attributes to the
META tag, but the grouping problem is not solved there.
Another problem with the META tag in HTML is the double storage of data,
once to be found in the head as metadata and again in the body of the document
as a visible text for human eyes. If someone changes the visible part of the metadata
document it seems to be correct for him in the browser, but it may contain
incorrect metadata. These problems can be solved when switching to RDF by
using DC and vCard vocabulary and object typing as we will describe below.
As already mentioned, the metadata files or title pages of the preprints contain
an abstract and MSC codes. Therefore the creation of the files should be
done by the authors of the papers themselves. To do so a detailed knowledge
about Dublin Core and HTML encoding is necessary or a tool that cares for the
syntactical correctness. Such a tool, called the Mathematics Metadata Markup
Editor, was developed at Osnabrück in collaboration with E. Hilf, Th. Severiens,
M. Jost and M. Kaplan.
This tool has been successively enhanced to introduce features such as controls
on the input, MSC browsing, and the output of Dublin Core metadata encoded
in HTML in a first version. The current version additionally supports RDF.
The author of a paper can type in the respective metadata and via mouse click
the metadata file is generated by a perl script. The Mathematics Metadata Markup
Version 3.1 tool can be used remotely or downloaded for local installation
from ftp://ftp.math.uos.de/pub/MMM/.
Now the stored metadata guarantee a much higher quality in retrieval than for
example a full text search on the original documents. On the one hand the result
sets are more specific and on the other hand the results can be presented in a well
structured way.
How documents enter the system and how they are presented
Once the metadata are stored on a WWW server they must be collected in some
way. However, the whole document cannot be stored in a central index. The copyright
of the authors allows the storage of copies for private or personal use, but
it is forbidden to keep them in a database and distribute them without the permission
of the author.