Rome Wasn't Digitized in a Day - Council on Library and Information ...

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framework to <strong>in</strong>tegrate several archaeological digital libraries (Shen et al. 2008). They developed a
doma<strong>in</strong> metamodel for archaeology <strong>in</strong> terms of the 5S model and focused particularly on the
challenges of digital library <strong>in</strong>tegration. The architecture of ETANA-DL consists of a “centralized
catalog and partially decentralized union repository.” To create the centralized union catalog they used
mapp<strong>in</strong>g and harvest<strong>in</strong>g services. ETANA-DL also cont<strong>in</strong>ues to provide all the services offered by the
<strong>in</strong>dividual digital libraries they <strong>in</strong>tegrated through what they term union services:
Union services are new implementations of all the services supported by member DLs to be
<strong>in</strong>tegrated. They apply to the union catalog and the union repository that are <strong>in</strong>tegrated from
member DLs. The union services do not communicate with member DLs directly and thus do
not rely on member DLs to provide services (Shen et al. 2008).
The authors stress the importance of provid<strong>in</strong>g <strong>in</strong>tegrated user services over an <strong>in</strong>tegrated digital
library, while still develop<strong>in</strong>g an architecture that allows the <strong>in</strong>dividual libraries to reta<strong>in</strong> their
autonomy.
In agreement with Kansa et al. (2007), the creators of ETANA-DL also warned aga<strong>in</strong>st attempt<strong>in</strong>g to
create one universal schema for archaeology:
Migration or export of archeological data from one system to another is a monumental task that
is aggravated by peculiar data formats and database schemas. Furthermore, archeological data
classification depends on a number of vaguely def<strong>in</strong>ed qualitative characteristics, which are
open to personal <strong>in</strong>terpretation. Different branches of archeology have special methods of
classification; progress <strong>in</strong> digs and new types of excavated f<strong>in</strong>ds make it impossible to foresee
an ultimate global schema for the description of all excavation data. … Accord<strong>in</strong>gly, an
‘‘<strong>in</strong>cremental’’ approach is desired for global schema enrichment (Shen et al. 2008).
Instead of us<strong>in</strong>g ArchaeoML or a subset, as with Open Context, the creators of ETANA-DL have
<strong>in</strong>crementally created a global schema and support data <strong>in</strong>tegration between different digital libraries
through the use of “an <strong>in</strong>teractive software tool for database-to-XML generation, schema mapp<strong>in</strong>g, and
global archive generation” (Vemuri et al. 2006). The three major components to the ETANA-ADD
tool are a database to XML converter, a schema mapper, and an OAI-XML data provider tool. The first
component “DB2XML” converts data from custom databases <strong>in</strong>to XML collections. “The end user can
open tables correspond<strong>in</strong>g to an artifact, and call for an SQL jo<strong>in</strong> operation on them. Each record of the
result represents an XML record <strong>in</strong> the collection, and the structure of the dataset determ<strong>in</strong>es the local
XML schema,” Vemuri et al. (2006) expla<strong>in</strong>ed, add<strong>in</strong>g that “based on this pr<strong>in</strong>ciple, the component
generates a local XML collection and its XML schema.” After a local XML collection is generated,
end users <strong>in</strong>teract with a tool called Schema Mapper, which leads a user through mapp<strong>in</strong>g the local
XML schema that has been generated for their database <strong>in</strong>to the global XML schema used by ETANA-
DL. If a particular artifact type or other item is not available the global XML schema is extended to
<strong>in</strong>clude it. The f<strong>in</strong>al component is an OAI XML data provider that supports publish<strong>in</strong>g of the new
XML collection as an OAI data provider. Thus, the ETANA-DL created a system that allowed for an
almost-lossless conversion of <strong>in</strong>dividual databases <strong>in</strong>to their own universal schema and created an
<strong>in</strong>tegrated archaeological digital library from three <strong>in</strong>dividual ones that can now be searched
seamlessly.