Databases Reference
In-Depth Information
They have (by default, at least) a simplistic reading strategy, “top-to-bottom/left-to-right,”
making it difficult and boring to wait for the relevant piece of information.
They fail to convey the overall organization of the page, with the relative priorities of the
different parts.
The selection of the navigational commands (e.g., links in a web page) is difficult and cum-
bersome. While in theory, it is possible to “confirm” the selection while “listening” to a link,
in practice; due to synchronization problems (of the audio with the current position on the
page), it almost never works.
Page layout and the “graphic's semantics” (that is, font size and color, position on the page) are
completely lost: the metallic voice of the screen reader will read one by one all the pieces of
information of the page with the same emphasis and tone (the landmarks, the main content,
the service links,…), as if they all shared the same degree of importance.
Images that convey essential pieces of information are not processed by the screen reader, that
is, only able to read an image's description (if available).
The point is that they basically read what appears on the screen, with a “book-reading” strategy, as
if it were the most plausible equivalent to the “at a glance” comprehension of a sighted user. The key
to finding a proper solution is to separate the
visual
from the
audio
experience: not all that is written
or visualized must be read; not all that is read must be visualized on the screen.
A set of accessibility guidelines have been developed (essentially for web interfaces) that may
help designers fill the gaps left by current standards (e.g. ,W3C-WAI guidelines) and effectively
conceive and deploy applications that are accessible and usable in an
oral navigation
. Innovative design
guidelines for supporting “accessible” access paradigms, attempting to go further the limitations of
the existing standards are the following:
Navigation strategies: a number of problems for accessibility stems from the practice, for the
web and other applications, of forcing the user to “go back” to already visited pages or menu. This
practice is ineffective for “normal users” and devastating for blind users (who must go through the
whole page before getting to the point of interest). To solve this issue, the designer should be able
to communicate the content to the user in a well-structured and understandable way, keeping the
displayed text as short as possible. This leads the designers to separate the concept of “topic” from
the concept of “page” and to create an application where each topic is made up from different pages,
each one related to a point of view or aspect. The main drawback of a structure like the above is
that it makes the back button of the browser completely useless in most cases. This button acts as a
syntactic back, while what is needed in an information intensive web application is a semantic one,
allowing the user to go backward through the topics, instead of browsing all the already visited pages.
This is much more important when dealing with accessibility concerns: a visually impaired user has
to listen to a significant part of each page to understand what the page is about, even if he/she is
going back through her history and knows exactly which page he/she is interested in. Implementing
