Abstract
We are intrigued by the problem of Web Accessibility. While it is somewhat intuitive to
imagine the barriers a disabled person may face in accessing content on the web, they are
not the only segments of users facing accessibility challenges. For instance, users with poor
English abilities, or users with less domain exposure, or users with different thinking levels also
face access barriers when reaching out to mainstream targeted public content. English-only
text for the non-English users, technical jargon for the non-technical, scholarly material for the
novice user, and local cultural references to those uninitiated may also be seen as barriers to
accessibility. To such non-mainstream users,who are often in the minority, the content on the
web – which is often designed for the majority – could, at times, be perceived as complex,
foreign, incomprehensible and even inaccessible. In our work, we are focused on this aspect
of the Web Accessibility problem.
We adopt the existing social technique of Renarration as a mechanism to overcome the
accessibility problem. At a social level, when humans communicate with a diverse group of
listeners, they vary the content to suit the needs of differing communities of their users. For
example, a child who is trying to discuss a new mod1
in a game may elaborate it more for a
fellow gamer, but may instead simplify it for a parent. Similarly, a scholar may formalize an
explanatory text for a fellow scholar, but may simplify or abstract the same to suit the needs of
a conventional listener. We use the term renarration to describe this act of generating a variant
version of the content from an original source. More formally, renarration can be treated as a
semantic transformation function applied on a given web page to generate a variant.
In our work, we have chosen to overcome some of the accessibility barriers on the web by
applying the technique of renarration to it. And, we equate renarration of web content to a
semantic transformation function. And finally, we aspire to find a web architecture that would
facilitate such semantic transformation of web content. Given this, the problem statement
for our research can now be stated as: What is that web architecture that would enable one or
more volunteer users to manipulate, modify, process or transform published web content into one or
more alternate views, such that each variant view now may deliver a different meaning to its targeted
community of viewers?
We move towards the solution space by reviewing the current approaches that are already in
use, and also by exploring any earlier work from the e-publishing industry. The design of our
solution is further informed by a series of nearly two dozen research undertakings consisting
of multiple surveys and experiments.
As part of our research, we also explore the theoretical underpinnings for semantic transformation. We study the notion of ”semantics” (as applied in Computer Science literature), and
also the notion of ”transformations” as discussed in the mathematical disciplines of geometry
and algebra. Through this work, we capture our notion of semantic transformation of web
content in an abstract, symbolic notation.
Citing ease of use for non-technical users, we focus on the notion of style sheets as one of the
many ways to transform web content. As part of this study, we explore the general notion of
style sheets and see how specific style sheets – namely, the popular XSLT and CSS style sheets
– have been used on the web. We take an abstract view of CSS as a transformation function
t operating on HTML marked content c and augmented by style information s, resulting in
t = f(c,s). Our notion of semantic transformation is informed by this abstraction and is
represented as yet another semantic transformation function t = f(c
0
, l, a, n) where f is still
a transformation function, c
0
is now the semantically annotated source, l is the location and
description of the semantic structure imposed upon the page by the user, a is the new set of
actions that are inclusive of semantics, n represents the conditions that are to be applied, and t
is the transformed target page. We call this new semantically oriented style sheet as Semantic
Style Sheet or SSS.
We take the core ideas behind CSS rule-set and use that to inform the design of our SSS. For
instance, the notion of a rule-set underlying a CSS is given by selector : { property : value}. We
enhance this rule-set in three dimensions, and infer a simplistic rule-set representation for SSS,
which is given as locator : { ( action , condition ) } where {attribute : value} pairs are predefined
for each of the locator, actions and conditions parameters.
To automate the better instrumentation of a web page we found the conventional tree
metaphor inadequate. We further explore other conceptual representations of a web page and
present an ontological model as our r