Testing EAD Encoding in the Texas Archival Resources Online (TARO) System with Textual Analysis Techniques

Electronic archival finding aids encoded in Encoded
Archival Description (EAD) are transported across
networks and rendered into HTML for display on the browser.
Considering the time, effort and money involved in marking
up the finding aids, has the markup been used for retrieval
purposes? Has the multilevel hierarchical nature of finding aids
been used for searching? A few online EAD tag based retrieval
systems that process queries look for occurrences of the search
term in the corresponding EAD tag, but do not seem to address
subject- or topic-based queries. This study explores the
possibility of using the content of specific EAD tags for subject
retrieval purposes. We studied the consistencies, commonalities
and discrepancies in usages of various critical tags across
repositories participating in the Texas Archival Resources
Online (TARO) project. These usages were compared to EAD
tagging guidelines as well as TARO guidelines. We identified
the <abstract>, <scopecontent> and <bioghist>
tags as good representatives of the finding aid from standard
archival descriptive practice and examined their content for a
sample of repositories within TARO. The content of these tags
was processed using text processing techniques to further study
and arrive at possible similarity metrics to identify similar
finding aids. We feel this would help evaluate EAD as an
information retrieval tool within TARO and if our experiments
help conclude that EAD can be effective as such a tool (or can
be made effective by better descriptive practice), then the
prospect of creating a highly interconnected web of finding
aids exploiting the hierarchical nature of EAD is possible.
This study was conducted on 1226 EAD encoded finding aids
from nine archiving institutions which are part of TARO. Our
study was conducted in three phases. First, we verified the
usage of EAD tags across repositories within TARO with an
aim of determining if there exists a core set of tags within these
finding aids. This part of the study was motivated by the
underutilization of the Dublin Core tags as reported by Shreves,
Kirkham, Kaczmarek and Cole and Ward. From this part of
our study we arrived at a core set of 27 EAD tags from the
entire EAD tag library comprising 146 tags. These 27 EAD
tags form a superset of the tags deemed mandatory by ISAD(G)
as well as the EAD tagging guidelines of other archiving
institutions. Additionally, we observed the varied usage of the
hierarchy of these tags within these finding aids and very limited
usage of tags to achieve electronic linking between documents.
In the second part, we studied if these finding aids have been
encoded according to standard archival descriptive practice
(i.e. if the text within these EAD tags was appropriate). This
was achieved through text processing involving extraction of
the text from the specific tags and processing these to arrive at
a vocabulary. We conducted this study on the part of the finding
aids corresponding to the University of Texas Alexander
Architectural Archive (UTAAA) and University of Texas Benson
Latin American Collection (UTLAC) repositories. Comparisons,
of the vocabularies of the <abstract> tag between two
different repositories indicate that the vocabularies for the said
repositories are quite distinct. We found that the content of
different tags has different word counts and correspondingly
different vocabulary sizes. Additionally, we observed that up
to 65% of the total word count in each of the three tags studied
(<abstract>, <bioghist> and <scopecontent>)
represents the vocabulary, thus indicating that significant
information is embedded in the textual content of each of these
tags.
In the third step, using the vocabularies obtained, we
represented these finding aids as vectors in the vocabulary
space. In such a vector representation of finding aids, we
compared finding aids using a cosine similarity in conjunction
with Term Frequency-Inverse Document Frequency (TF-IDF)
weighting. The TF-IDF scheme weights rarely used words
higher than commonly used words, and also accounts for the
size of the document. We then clustered these finding aids with
an online clustering tool (wCLUTO) using the agglomerative
clustering algorithm. The agglomerative clustering groups
finding aids based on the similarity of content, resulting in a
tree of documents. The lowest levels of the tree correspond to
individual finding aids and the highest levels of the tree
correspond to the entire sets of finding aids. Our study focused
on low-level clusters, which are of particular interest to
archivists, as these clusters address the descriptive material
embedded in the various EAD tags. To determine the
similarities between finding aids, we extracted vocabularies
for individual tags like <abstract>, <scopecontent>
and <bioghist> and clustered the finding aids based on the
similarity of textual content with respect to these individual
tags. Further, we combined the similarity relations between finding aids, based on these individual tags, to build a space
that encompasses the content similarity for a combination of
tags. Our clustering results on individual and combination of
tags are in agreement with the classification provided by the
curators of the UTAAA repository.
We conclude from our study that if finding aids are marked up
according to standard archival descriptive practice then they
yield meaningful content-based clusters of similar finding aids.
Further, we were able to demonstrate; i) the ability of forming
'neighborhoods' of similar finding aids using either individual
tags or a combination of tags, and, ii) that the 'neighborhoods'
were different for different tags or combination of tags. From
this idea of a 'neighborhood' of finding aids, we propose a
searchable interface for a repository of finding aids by means
of the EAD tags. This search facility, we think, enhances the
prospect of creating a web of similar and, thus, interconnected
finding aids, which, in turn would facilitate research in the field
of archives and help researchers form cliques by common
research interests and goals.
Our study demonstrates the ability to apply the text processing
techniques from the field of information retrieval to the field
of archives with a goal of enabling EAD encoded finding aids
transition to the digital world and be visible in the realm of
online documents and be accessible to researchers.
Bibliography
Shreves, S.L., C. Kirkham, J. Kaczmarek, and T.W. Cole.
"Utility of an OAI Service Provider Search Portal."
Proceedings 2003 Joint Conference on Digital Libraries. Los
Alimotos, CA: IEEE Computer Society, 2003. 306-308.
Ward, J. "A Quantitative Analysis of Unqualified Dublin Core
Metadata Element Set Usage within Data Providers Registered
with the Open Archives Initiative." Proceedings 2003 Joint
Conference on Digital Libraries. Los Alimotos, CA: IEEE
Computer Society, 2003. 315-317.