3.4 Making Accessible Text
Format all text using BookML where possible. Avoid uploading images of text. For mathematical formulae, BookML has scren-reader friendly output when formulated using MathJax (default) or the browser (using bmldisableMathJax{} around the formula).
When emphasising meaning in your lecture notes, it is most accessible to communicate this in a text-based way. This can be done alongside other methods of emphasis.
3.4.1 Emphasis in BookML
Sometimes, lecture notes use bold font or itallic font or coloured text as a method of emphasis. For use of colour, see Subsection 3.4.2.
When using BookML, the commands \textbf and \textit are assumed to be purely visual. This means that the .html for these is formatted in a way that screen-readers will bypass it. If, however, your use of bold or italics is to communicate meaning (including to communicate emphasis), you should use a different environment. This uses raw html. If you wish to use bold font as a method of emphasis, write the following into your pre-amble.
\newcommand{\textStrong}[1]{\bmlRawHTML{ <strong> #1 </strong>
}
\iflatexml\else \textbf{#1}
\fi}
Now, when you want to use bold font for emphasis, call the command \textStong{} instead of \textbf.
For italics, you would use:
\newcommand{\textEm}[1]{\bmlRawHTML{ <EM> [#1] </EM>
}
\iflatexml\else \textit{#1}
\fi}
and call \textEm{} in your LaTeX document.
3.4.2 Use of Colour in text
Colour should never be the sole communicator of information. While it can be useful for some students to see information colour-coded (example — common mistakes in red and correct answers in green), this alienates students who struggle to tell the difference between hues. All information used to understand the content should be provided in a text-based way.
If you use coloured text in your lecture notes, ensure that the contrast between background colour and text colour is at least 4.5:1. This website provides a way to check contrast of colours via hexadecimal input. Here, the background colour is white (hexadecimal #FFFFFF).
3.4.3 Headings and titles
BookML treats sections and chapters as different html pages. Your document title, chapter titles and section titles should be descriptive of the contents of that chapter. To change this behaviour, use SPLITAT (see BookML documentation).
3.4.4 Use of words from other languages
For a screen-reader to work properly, it needs to know which language a word belongs to. When using a term from another language which is not commonplace in English (i.e. eigenvector, which a screen-reader pronounces with a soft g sound in English), we need to declare this in LaTeX. Here I used:
\foreignlanguage{german}{eigenvector}
For more detailed documentation, see this guide from Overleaf.