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<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>From ZigZag™ to BigBag: Seeing the wood and the trees in online archive finding aids</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Ian G. Anderson</string-name>
          <email>I.Anderson@hatii.arts.gla.ac.uk</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>University of Glasgow 11 University Gardens Glasgow G12 8QH</institution>
        </aff>
      </contrib-group>
      <fpage>12</fpage>
      <lpage>17</lpage>
      <abstract>
        <p>This paper reports on a one year speculative research project that sought to test the technical feasibility, practical implications and usability of transforming an XML Encoded Archival Description (EAD) finding aid into an XML ZigZag™ structure and applying a relational browser interface.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;EAD</kwd>
        <kwd>ZigZag™</kwd>
        <kwd>Ted Nelson</kwd>
        <kwd>XML</kwd>
        <kwd>Browsing</kwd>
        <kwd>Visualisation</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>
        However, as more archival finding aids, of increasing complexity,
become available online the difficulty of seeing the 'wood from
the trees' increases. This is particularly the case when these are
implemented in Encoded Archival Description (EAD) [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. EAD is
an XML DTD for the creation of machine readable, cross
searchable archival finding aids and its creators consciously based
its structure on hierarchical analogue finding aids. Whilst this
provided an important comfort zone for archivists to migrate to
encoded finding aids, it is also meant EAD inherited the innate
difficulty of navigating hierarchical structures.
      </p>
      <p>Permission to make digital or hard copies of all or part of this work for
personal or classroom use is granted without fee provided that copies are
not made or distributed for profit or commercial advantage and that
copies bear this notice and the full citation on the first page. To copy
otherwise, or republish, to post on servers or to redistribute to lists,
requires prior specific permission and/or a fee.</p>
      <p>
        Whilst an archive's physical space, catalogue arrangement and
archivist’s assistance all help to guide users' navigation in the
analogue world, this paradigm does not easily translate to the
electronic. Nor has there been a significant body of research
established on archive user's information seeking behaviour.
Indeed there is little evidence that traditional archival
arrangement adequately served the needs of users in the analogue
world. It is unlikely, therefore, that replicating such arrangements
in the digital world would prove any more successful.
Where research on archive user needs has been undertaken a
range of characteristics have been discovered that suggest a more
flexible approach to archival access is required. The very earliest
studies in the late 1990s indicated that time, training and access to
information about information were crucial barriers to electronic
access, even though this access had become a critical component
of historians’ research methods [2]. Later studies have revealed
the plurality of historians’ information seeking behavior but also
the need for both research and archival context that was common
amongst the most popular methods [3] and the importance of
intermediaries in the use of online material [
        <xref ref-type="bibr" rid="ref2">4</xref>
        ]. Academic
historians require multiple pathways to access primary research
materials and the need for user education on electronic searches
suggests that current provision hinders access [
        <xref ref-type="bibr" rid="ref3">5</xref>
        ]. Moreover, the
need for orientation in even the most experienced user has been
emphasized [
        <xref ref-type="bibr" rid="ref4">6</xref>
        ].
      </p>
      <p>
        Archive portal sites such as the Archives Hub, A2A, AIM25,
ANW and SCAN are evidence of the desire to search across
collections and repositories but typical means of browsing or
displaying search results, such as lists and directories, severely
restrict users’ ability to see where they are, how they got there
and where they can go next [
        <xref ref-type="bibr" rid="ref5">7, 8, 9, 10, 11</xref>
        ]. Providing linked
‘cross-walks’ such as subject keywords, functional descriptions,
person, place and corporate names can only go so far in
addressing this problem. Points at which these cross-walks
intersect can not easily be displayed and users wishing to move
from one to another need to repeat searches or navigate up and
down the hierarchy.
      </p>
      <p>This problem increases exponentially where related material is
held in different series, collections or repositories. In these
circumstances trying to follow a particular person, function or
responsibility is extremely difficult. In following one path, users
lose sight of others, where they cross and what their relationships
are. In essence the multidimensional relationships that exist
within the finding aid are subordinate to its hierarchical structure.
The threads of this research all combine to suggest that a means
by which archive users can quickly and intuitively orientate
themselves within collections and identify the relationships and
context of the resources they are viewing would be immensely
beneficial. This project, funded by the UK's Arts and Humanities
Research Council (AHRC) through a one year speculative
research grant, sought to test a novel approach to structuring and
visualising archival information by applying a relational browsing
interface to EAD finding aids that have been transformed into a
multidimensional structure.</p>
    </sec>
    <sec id="sec-2">
      <title>2. A MULTIDIMENSIONAL SOLUTION</title>
      <p>One potential solution to this problem is to structure and visualise
this information multidimensionally. For example, repository,
collection, date and function could each be a separate dimension,
rather like lines on a London Underground map. Therefore, a user
viewing the person name dimension (or line) would see each
individual represented in a finding aid as a cell. This person may
appear in different parts of a collection, separate collections at the
same repository and at other repositories, quite possibility related
to different organisations, functions or roles. Whilst well
developed finding aids can make these links, it is very difficult for
users to see and navigate them.</p>
      <p>One such means of organising information multidimensionally is
the ZigZag™ concept developed by Ted Nelson [12]. In other
words, a piece of information can exist in different places at the
same time and have many connections to other information that
may also exist in more than one place. The beauty of the
ZigZag™ system is that the user can bring multiple instances of
the same information into one view and by changing the
dimensions can instantaneously see how the related bits of
information are connected. Thus the user is always presented with
a locally relevant view of the information, irrespective of how
complex the structure is, and without losing the ability to navigate
and view all the interconnections. The possibility to represent
archival information in this way may provide both functionality
and usability that reflects the deep interlinked structures of today's
online finding aids. These additional dimensions could be used to
provide a whole range of context specific information, such as
related bibliographies, digital surrogates, user comments and help
files. This would allow online finding aids to move from an
access tool to an expert system.</p>
      <p>The advent of XML encoded finding aids, particularly EAD, and
the wide scale implementation of descriptive standards made this
an ideal time to test the viability of a ZigZag™ structure and
visualisation.</p>
      <p>The number and extent of dimensions it is possible to represent,
does of course, depend upon the quality and extent of the
underlying data. For this project two finding aids, Gateway to
Archives of Scottish Higher Education (GASHE) and
Navigational Aids for the History of Science and Technology
(NAHSTE), provided by the University of Glasgow Archive
Services were selected [13, 14]. These finding aids provided the
project with the opportunity to test the concept against EAD, the
descriptive standards General International Standard Archival
Description (ISAD(G)2) and International Standard Archival
Authority Record for Corporate Bodies, Persons, and Families
(ISAAR(CPF)). The GASHE finding aid also including function
and activity 'cross walks' within it. Both finding aids cross
multiple collections and repositories.</p>
      <p>Overall, the project aimed to achieve 'proof of concept' status
that it was technically feasible to map between EAD and a
ZigZag™ structure; that the transformation between the two could
be automated; that a web based interface could represent the
multidimensions and; that it supported more intuitive browsing
for users.</p>
    </sec>
    <sec id="sec-3">
      <title>3. DEVELOPMENT</title>
      <p>Several working examples of ZigZag™ structures have already
been created in other projects using Perl, C, Python and Java to
run on Windows, Linux and Mac. Initially the most promising of
these for this project was the combination of XML, XSL and
JavaScript, successfully demonstrated by Les Carr at the IAM
Research Group, University of Southampton on a map of the
London Underground, see Figure 1 below [15].
Taking this project as an inspiration and re-using the ZigZag™
for Web Browsers XML dialect kindly provided by Les Carr the
project's functional and technical specification was defined using
the Unified Modeling Language (UML), in particular use-case
and activity diagrams. During this process it was decided that
static, rather than 'on the fly', transformation of the finding aids
were most appropriate in this context, given that the source data
was static and the additional computational demands that online
dynamic transformations would entail.</p>
      <p>Mapping the EAD finding aids to the ZigZag™ structure through
XSL was the first major project milestone. The finding aids
actually comprise hundreds of files, in the case of GASHE, an
XML EAD file using the ISAD(G)2 descriptive standard, XML
ISAAR authority file, XML FANDA file (for functional and
activity descriptions) for each individual collection, in each
repository. The relationship between these files needed to be
understood before the EAD file could be mapped to the ZigZag™
structure. At this point the application was named BigBag, partly
as it was a nice alliteration of ZigZag™ but also because the
dimension lines between cells in the mapping diagrams resembled
the large string shopping bags used to carry groceries, see Figure
2 below.
Thirteen EAD features were mapped to the ZigZag™ output tree
by the projects 'Transform Finding Aid to ZigZag' stylesheet so
each of the many ways to categorise an archival component
became a dimension: subject, repository, personal name, location
(shelf number etc.), container (box, folder, album etc.), format
(book, film, letter etc.). function, date, century, business or
corporate name, a daisy chain crossover linking all archive
components, a crossover linking collection and series, and a
crossover linking series and objects. As the underlying structure is
one of linked circular lists the same cells may appear
simultaneously in different orders in several linked lists.
The stylesheet had to manage some peculiarities of EAD and
handle function, subject and place dimensions differently from
other elements as multiple elements were possible, nested within a
&lt;p&gt; tag. For example the stylesheet had to avoid adding the
current place if it was the same as a place that had already been
added, unless the current place was a sibling of the place that had
already been added.</p>
      <p>The stylesheet expected six required EAD elements, sixteen
optional EAD elements and six optional multiple and recursive
EAD elements. Seven escaped character codes were also stripped
from the input tree as well as 13 characters that were illegal in
JavaScript.</p>
      <p>The cells of the output tree could be one of three types: collection
(this included collection, fonds, class and record group
descriptions), series (this included series, subfonds, subgroups or
subseries descriptions) or object (this included item or file
descriptions). Fragments from the XML ZigZag™ structure are
provided in Figure 3 below.
&lt;dimensions&gt;
&lt;dimension name="AllComponentsandObjects"
description="All Components and Objects" /&gt;
&lt;dimension name="12thCentury"
description="12th Century" /&gt;
&lt;dimension name="Subject:Accounting"
description="Subject: Accounting" /&gt;
&lt;dimension name="Date:1971/1993"
description="Date: 1971/1993" /&gt;
&lt;dimension name="Repository:Glasgow
Caledonian University Archives"
description="Repository: Glasgow Caledonian
University Archives" /&gt;
&lt;dimension name="Format:file"
description="Format: file" /&gt;
&lt;cells&gt;
&lt;cell n="1"&gt;
&lt;url&gt;http://www.gashe.ac.uk:443/cgibin/view_isad.pl?id=GB-1847GP&amp;amp;view=basic&lt;/url&gt;
&lt;title&gt;Records of Glasgow Polytechnic
formerly Glasgow Collegeformerly Glasgow
College of Technology&lt;/title&gt;
&lt;content&gt;fonds&lt;/content&gt;
&lt;link direction="AllArchiveComponents"
posward="2" /&gt;
&lt;link
direction="AllCollectionsandComponents"
posward="2" /&gt;
&lt;link direction="20thCentury"
posward="2"&gt;&lt;/link&gt;
&lt;link direction="Place:Cowcaddens Road
Glasgow" posward="2"&gt;&lt;/link&gt;
&lt;link direction="CorporateName:Glasgow
Polytechnic" posward="4"&gt;&lt;/link&gt;
&lt;link direction="Date:1971/1993"
posward="2"&gt;&lt;/link&gt;
&lt;link direction="Repository:Glasgow
Caledonian University Archives"
posward="2"&gt;&lt;/link&gt;
&lt;/cell&gt;
The transformation from EAD to ZigZag™ used Microsoft's
Command Line Transformation Utility (MSXSL). This process
was a two step transformation of archival finding aid data, from
EAD XML into ZigZag™ XML and then into ZigZag™ HTML.
Les Carr's ZigZag™ for Web Browsers is limited to 40 cells so a
test file was selected that outputted 27 cells.</p>
      <p>However, initial tests of a sample of data from the GASHE
finding aid using Les Carr's XML dialect and JavaScript interface
proved problematic. The transformation produced a functionally
correct interface, but one that had limited usability, comprising
hundreds of small black arrows dispersed across several screen
widths, see Figure 4 below. Furthermore, even with the small
sample data set, well specified PCs (dual core Pentium
processors, 2GB RAM and 256MB dedicated graphics memory)
were returning warnings that the JavaScript was causing the
computer to run slowly. Although the number of cells was small,
the number of dimensions associated with each cell in GASHE
was far greater than in the original London Underground demo.
These factors suggested that the JavaScript development path was
unlikely to scale well enough for the amount of data and number
of relationships required or provide sufficient complexity for the
visualisation.</p>
      <p>The second version of the interface, and the first to be tested with
users, added a colour keyed sliding selector for the various
dimensions as well as drop down menus for selecting instances of
dimensions and archive components. A breakout box that linked
to the original finding aid for each selected cell was also added as
well as history and home buttons, see Figure 5 below [18].
Whilst the appearance of the interface and the efficiency of the
data handling could undoubtedly have been improved a decision
was taken to seek an alternative means of visualisation. Initially
an SVG interface was an attractive solution. It would keep the
data within the XML family and the Parip Explorer project had
successfully demonstrated a visualisation style that could suit the
data [16]. However, the lack of project experience with SVG and
the limitations of browser support led the project, after further
research, to develop its interface using Macromedia/Adobe Flash
based on an original idea by Moritz Stefaner [17]. Stefaner's
relational browser for the CIA World Fact Book provided the
underlying physics for an interface that positioned the selected
'cell' in the centre of the screen with lines spanning out to related
cells of information. Selecting an outlying cell brought this to the
centre of the screen and redrew the relationships. In other words it
provided users with locally relevant view of their selected
information without losing sight of the immediately bigger
picture. An initial trial with a simple greyscale version of the
relational browser interface demonstrated that it was capable of
being modified to reflect, in part at least, the underlying ZigZag™
structure.
A small, targeted sample of six people, two archivists, two
historians and two students were selected to test this first version.
Although the feedback was positive on the whole, with
participants finding the interface clear, intuitive and supporting
their browsing behaviour it was also evident that the
multidimensionality of the underlying ZigZag™ structure was not
being adequately expressed. Stefaner’s relational browser only
had to express one type of ‘part of’ relationship between two cells
at a time and employed a single line to do so. However, with the
finding aid ZigZag™ data there are potentially many different
relationships between each cell that a single line cannot
adequately convey. The sliding dimension selector was an attempt
to overcome this problem but users did not like having to scroll
through each dimension on the slider to see if it applied to their
selected cells. It was evident that a means of immediately
representing the number and type of relationships between cells
was needed.</p>
      <p>The next version of the interface, version three, tested the
technical possibility of having multiple lines, each representing a
different dimension, connect each cell and for the width of these
lines to reflect the number of instances within that relationship.
Once the project had established that this was technically and
aesthetically possible version four of the interface was released.
This removed the sliding dimension selector and replaced it with a
simple key to the coloured lines. The format of the breakout box
to link to the original finding aid was simplified and the screen
split to show the original finding aid to the right [19]. In this
version of the visualisation the colour of the line again indicates
the dimension type with line widths indicating the number of
instances for each type, the thicker the line, the greater the
number of instances. Icons indicated whether the cell data existed
at the collection, series or object level in the original finding aid,
see Figure 6 below.
The same six users who previously evaluated the project were
shown the final version of the interface. In this case the
underlying relationships within the data were agreed to be more
explicit and enhanced the browsing of the finding aid data.
However, users now instinctively wanted to click on the
connecting lines to isolate a particular dimension, a functionality
that was not possible, rather than use the dimension instance drop
down menu. Furthermore, bugs and inconsistencies, particularly
in the way dimension instances were selected significantly
hampered users. Selecting a subject dimension form the drop
down menu did not alter the cell display, an error that was not
present in the previous version of the interface, and an additional
erroneous subject instance also appeared on the menu.
By this late stage in the project time was a major constraint and it
was not possible to either complete the scheduled interface testing
or implement the zoom in and out function, or the add and
subtract cells feature. Indeed it was a struggle to get the final
version of the visualisation working in time at all.</p>
    </sec>
    <sec id="sec-4">
      <title>4. STRENGTHS &amp; WEAKNESSES</title>
      <p>In part the project has fulfilled its main objectives. It established
that it was conceptually possible to map from EAD to ZigZag™
and that a stylesheet could be developed that automated this
process. However, it was not possible to establish that this
transformation could be undertaken on all instances of EAD
finding aids. Even working within the GASHE collection,
variations in EAD encoding practices posed a challenge to
efficient transformations. In part this is an inherent weakness of
EAD in that its minimal compliance requirement amounts to little
more than a collection description, akin to a minimally compliant
TEI header. In the projects test data the lack of entity declarations
for special characters also interfered with attempts to create
suitable visualisations. In retrospect, editing the GASHE EAD
prior to transformation would have created a far more efficient
process. However, in trying to create a transformation that would
be applicable to real life situations it would be unrealistic to
expect archivists to amend their EAD files in order to
accommodate our visualization. One useful spin-off from this,
however, was the development of a set of EAD templates for the
NoteTab text editor that placed greater constraints on coding
choices. The objective of this exercise was that archivists might
adopt them when creating new EAD finding aids and so avoid
many of the common problems found in the EAD finding aids
that hindered this project.</p>
      <p>Although the project was able demonstrate the technical viability
of an XML ZigZag™ for web browsers on larger and more
complex data than the London Underground demo, this was not
significantly so and time did not allow for the transformation and
visualisation of the entire GASHE finding aid let alone test the
stylesheet against NAHSTE.</p>
      <p>Throughout the project a difficult balance had to be struck
between refining and testing the stylesheet against larger and
more varied sets of source data and developing a meaningful
visualisation to test with users. In the end neither component was
as fully developed as it could have been, but the project would
have failed in an important respect if it had successfully
transformed a large amount of data without any means of
displaying the results. In retrospect the project may simply have
been too ambitious in its scope.</p>
      <p>After a few false starts the project did create a visualisation that
reflected the underlying multidimensionality of the ZigZag™
data, albeit imperfectly. Although the fourth and final interface is
the closest conceptually to the goals the project set itself its
limited development time, even compared to the second version,
proved a hindrance to establishing with certainty that this
provided a significantly more beneficial interface to online
archive users. It was never the projects intention to undertake
extensive user evaluation or usability testing but within the
constraints of what was possible the generally positive feedback is
sufficient to suggest that the approach adopted does bring benefits
for browsing archive finding aids online. How great those benefits
are, for what type of information seeking behaviour and in what
circumstances are questions that this project is unable to answer.</p>
    </sec>
    <sec id="sec-5">
      <title>5. CONCLUSION</title>
      <p>Perhaps inevitably for speculative research this project ultimately
raises more questions than it answers, but has at least
demonstrated sufficient merit to warrant those questions being
investigated further. In particular the relative importance of the
underlying EAD finding aid, ZigZag™ structure and visualisation
on the end user's understanding of the data needs to be examined.
It is the intention to continue this research by creating a set of
alternative structures and visualizations based on the same
underlying archive data – a relational visualisation directly on an
EAD fining aid; archive data that has been directly inputted to a
ZigZag™ structure rather transformed; an EAD to ZigZag™
transformed visualisation (essentially an updated version of the
current visualization) and; the archive data as displayed in its
native state.</p>
      <p>These alternative representations will provide a test bed through
which end users understanding of the archive data will be
examined using reception theory. Reception theory, sometimes
called audience response theory, is a version of reader response
theory that first developed in literary studies and was
subsequently extended to include performance works. Reception
theory proposes that a text does not have an inherent meaning, but
meaning is created within the relationship between the text and
the reader, shaped by the reader’s background, influences and
biases. By applying this theory to archival data it is hoped to
explore the extent to which meaning is created by the user, is
inherent to some extent in the data itself, and/or meaning is
shaped by the way in which the data is structured or visualized.
There is also the potential for the approach tested here to be
applied to information domains other than archives. Since this
research was completed a brief market analysis was conducted to
try and identify other areas that might benefit from this approach.
Although this survey was by no means comprehensive, and there
are a range of commercial data visualization products already
available, the areas of social networks, personal or business
contact lists, customer relationship management and enterprise
relationship management are potentially new areas that future
research could address.</p>
    </sec>
    <sec id="sec-6">
      <title>6. ACKNOWLEDGMENTS</title>
      <p>My thanks to the AHRC for funding, the Humanities Advanced
Technology and Information Institute and the Faculty of Arts at
the University of Glasgow for additional support, Lesley
Richmond and Victoria Peters of University of Glasgow Archive
Services for the supply of data and advice, Les Carr at the
University of Southampton for permission to re-use his XML
ZigZag™ for Web Browsers dialect, Moritz Stefaner for
permission to re-use the underlying design of his relational
browser and Steve North, Research Assistant, for his creativity,
dedication and hard work.</p>
    </sec>
    <sec id="sec-7">
      <title>7. REFERENCES</title>
      <p>
        [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] EAD http://www.loc.gov/ead/
[2] Andersen, D.L. “Academic Historians, Electronic
Information Access Technologies, and the World Wide Web: A
Longitudinal Study of Factors Affecting Use and Barriers to that
Use”, The Journal of the American Association for History and
      </p>
    </sec>
  </body>
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</article>