[Music]
Hello, my name is Alejandro Rodríguez Caso
and I am a professor at the Department of
Artificial Intelligence at UNED.
This video is entitled "Accessibility of digital texts.
First part". The text is composed of a series of
numerical, orthographic symbols of other
types that represent the natural language.
To begin with, we will agree that a
fundamental characteristic of the text
is the language in which it is written.
Sometimes the entire document is written
in one language, on other occasions
it contains some fragments in another.
For example, in the phrase "The Rolling Stones
published their album Sticky Fingers in 1971".
For a screen reader to pronounce correctly, we must label which
parts are in Spanish and which parts are in English.
In HTML we use the "lang" label to
indicate the language, either for the
general document or in those fragments that need it, using, for
example, the "span" label. In a similar way, in a processor, we must
Mark the language of each part of the text.
It depends on the program we use, but
in general this option appears in the "Tools" menu.
First, we will select the language of
the entire document and then we will select the text fragments for
which another language must be indicated.
"Nobody is born learned", as they say in my land.
We all, at some point,
come across a topic that is new and unknown to us.
That is why it is so important that our text has a certain glossary,
in which you can consult the meaning of those that are new,
including acronyms.
Having a glossary is useful for anyone,
especially for those with difficulty understanding the
written text, as is the case of some deaf people or those who have
general problems to understand or remember.
Another issue. Sometimes we want the text to appear with a
certain structure.
For example, with this table, students of a course can know,
for each week of the course, first
column, the task they must perform, second
column, and the delivery date of that task, third column.
For a person who uses a screen reader to be able to handle a
table well, it is important that it is regular, that is, that a cell is
defined only by a number of columns and a number of rows.
Text processors usually offer us the tools "draw" and "erase",
usually represented with a pencil and an eraser, which allow
to join or divide cells in a table. They are very useful tools to
modify the structure of a table, but
from the point of view of accessibility,
for me, they are rather dangerous friendships.
If we erase the separation between
two adjacent cells with the eraser to
join them in one, taking advantage of the
fact that the delivery date is the same,
the result will be an irregular table, in which, for example, a cell
corresponds to two rows at the same time. Bad vibes.
When going through a table with a screen reader, it is also a help
to know which cells are used as headers.
In this case, the cells of the first row are the header.
The way to indicate it in a text processor is not very obvious,
the truth. We must first select that row
of the table and indicate that it must be repeated on each page.
If, on the other hand, we are editing in HTML,
we achieve that goal using the "th" labels.
Another recommendation, especially useful in those tables that have
some complexity and for those who have
difficulty understanding, is to give
instructions on how to use the table.
In our case, which is quite simple,
we would have to say "Choose a week in the first column" and in the same
row you will find what task you must
deliver and the deadline to deliver it.
In the table there are as many rows per
week as tasks to be delivered in that week.
Another way to structure the text is to use lists, either numbered or
not numbered. The lists must be labeled properly so that a
screen reader user knows when they start and when they end and so that
they can know the order that an element occupies in an ordered list.
In text processors we achieve this by
using the styles available for them.
Apart from contributing to accessibility,
using these styles helps us as
authors because we can change the shape of the lists' thumbnails
, for example, change the points by scripts.
Another advantage, by adding
a new element, the numbered list will be automatically reordered.
In HTML there are labels to create a numbered
list, "ol" or a non-numbered list, "ul",
and to label each element of the list, "li".
Let's now talk about what source to use in our text.
Serif-free sources are recommended, that is,
without the addition that sources such as
Times New Roman have. Some serif-free sources also have
legibility problems. This is the case of the
Arial source, in which it is not possible to
visually differentiate between the capital "I" and the lowercase "L".
A type of recommended source from
the point of view of accessibility is the Verdana.
In addition, as for the source, it
is recommended to avoid, if possible, the use of
black and cursive. It is also important to guarantee a
sufficient size of the source, although
logically this will depend on the
device and the conditions in which the text will be read.
Another very important aspect, the contrast between
the colors of the source and the background.
It must be as large as possible. A classic solution, a black source
on a white background, always works. If we use other color combinations,
we must always check that we meet the
criteria 1, 4, 3 of the guidelines for
accessibility of web content, which
establishes a contrast of at least 4.5 over 1.
There are many free tools on the web that allow us to know if our
combination of colors satisfies this criterion.
On the other hand, it is recommended
to use the justification on the left,
because the centered justification can generate too large blank spaces.
between words, which makes it difficult
for some people with low vision to read.
How good it is to be able to choose for
our text the type of source, the size, the contrast.
That is precisely why it is not recommended to use images to
present text. In the images we cannot
modify these properties and we are
making accessibility difficult.
The text, text is, remember, although sometimes.
we are tempted to use images. I give you an example, mathematical texts.
They are not linear, but they are
two-dimensional, like the solution of the
second degree equation. If we include
text as images, we will be preventing
many users from reading it, such as screen readers, or that others
have serious difficulties, such as those
who need to enlarge the image of the.
screen a lot. In our text we must include
mathematics as +ML. Does it mean that we must know that language?
Luckily not. We just have to make use
of a mathematical equation editor that
automatically generates it. Virtually all text processors have
a mathematical formula editor. Use it.
On the other hand, more and more HTML content editors have a
mathematical editor with +ML. Some of them are free.
We recommend that if you do not have one
in your school or university, talk to
the management or the person who manages the systems to provide them.
In summary, in this video on the accessibility of digital texts,
we have dealt with these issues. We have defined the text type content,
the importance of labeling the language, of
including a glossary, of making tables and
accessible lists, the type of source, its
size, the contrast with the background and
the text alignment, not using images to transmit text, how to include
mathematical text. There are other aspects of
accessibility of digital texts that we must attend
to. We will deal with them in another video.
See you soon.
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