October 2006 Volume 9 Number 4

Verifying contents
Figure 3. The page created with MS Word
Some of the actions due to obtain a universal and accessible content could be forgotten by the author that
sometimes prefers to write a fast draft and improve it by adding additional information later on. The system
provides a verification toolbar, depicted in the following Figure 4, to support the author in controlling the
correctness and completeness of his contents.
Figure 4. The verification toolbar
With the verification toolbar, the author can control the syntactical respect of all the guidelines which guarantee
universality and accessibility of the learning materials. A typical control verifies the presence of the required
description of images; in this case, two different alerts are provided (as depicted in Figure 5):
An error, every time a short description is missing. The short description corresponds to the alt attribute of
the img tag and is required to guarantee the accessibility of graphical information, thus the absence of a
short description it is considered as a heavy error (World Wide Web Consortium, 1999c).
A warning, related to every missing long description. The long description is needed for complex graphical
contents (e.g. charts, graphs, etc.), which need additional descriptive information to be understood by blind
people or by people accessing with no-graphical browsers (World Wide Web Consortium, 1999c), e.g. Lynx
(Lynx Project, 2006).
Figure 5. Alert messages
The automatic control can catch only syntactical errors, such as a missing description. It is substantially
impossible to automatically ensure the description will be adequate to the image. Other constraints to the
structure and the accessibility of contents could be activated through the verification toolbar such as the
hierarchical use of nested headings and the presence of summaries for data tables.
10