This guidance shows how to produce, potentially with little effort, accessible pdfs and low accessibility score
Important steps: (details below)
compile with lualatex instead of pdflatex (this is included in most pdf installations)
use the ltx-talk package instead of beamer for slides
use the Metadata below
See the sample files for slides with ltx-talk and a sample coursework
for images, use descriptive alt tags like in
\includegraphics[scale=.5,alt={A graph of demand and supply}]{equ.png}
or use artifiact if the image is for decoration
\includegraphics[scale=.8,artifact]{decoration.png}
It is important you latex installation is up to date
The minimum is to add the following first line to your tex code before compiling with lualatex.
\DocumentMetadata{
tagging=on,
pdfstandard={UA-2,A-4F},
lang=en,
tagging-setup={math/setup={mathml-AF,mathml-SE}}
\tagpdfsetup{table/header-rows = 1}
This will likely improve your score to the orange range, but to achieve green, if you have formulae, the following is needed as well. Unfortunately the following may impact overall accessibility: the tags you see in Acrobat (see below) may become gibberish instead of xml; but the information is still contained in a different way thanks to using mathml-AF.
\tagpdfsetup{math/alt/use}
Most pdf editors have a way to select lualtex instead of pdflatex etc. If you just want to try, write on the command line in your folder lualatex myfile.tex . Overleaf users see the guidance below.
To verify if your pdf file is accessible, there are a few options:
Convert it to a html file with https://ngpdf.com/ If the result is legible, your pdf is legible with nice formulae the pdf is likely accessible
Open with Acrobat, Choose the Menu (Windows), or the View menu (macOS) > Show/Hide > Side Panels > (accessibility) Tags and check if formulae have some alternative description.
Click on the red/orange/green accessibility icon in blackboard and see what it complains about.
Pdfs seem to capture formulae as images. This needs to be either amended (via tags) with alternative texts, or alternative formats like mathml.
A sample .tex of slides with ltx-talk
\DocumentMetadata{
tagging=on,
pdfstandard={UA-2,A-4F},
lang=en,
tagging-setup={math/setup={mathml-AF,mathml-SE}}}
%mathml-SE may be enough in principle, in particular if math/alt/use is not used below
\documentclass{ltx-talk} %the accessible beamer replacement.
%\documentclass[mode=handout]{ltx-talk}
\usepackage{graphicx}
\tagpdfsetup{table/header-rows = 1} % This is needed for tables
\tagpdfsetup{math/alt/use} %This is not required for state of the art, but needed for low blackboard scores
\EditInstance{footer}{std}{
element-order = framenumber,
separator = { / },
}
\title{An example of accessible slides}
\author{Christian Kellner}
\institute{University of Southampton}
\begin{document}
\section{Main content} %With ltx-talk, this section produces no ouput, but removes a complaint of the pdf accessibility. Structuring documents is important for accessibility
\maketitle
\begin{frame}\frametitle{A frame with math}
\[U(p)=\frac{\sum_{i=1}^n \omega_i p_i u(x_i)}{\sum_{i=1}^n \omega_i p_i}\]
\end{frame}
\begin{frame}\frametitle{A frame with a graph}
Here is a graph with an alt text. Note this alt text is the main source of manual intervention to make your pdfs accessible.
\begin{center}
\includegraphics[width=0.5\textwidth,alt={depiction of a risky urn,A, with 7 red and black balls each and an unknow urn, B, where we cannot see inside}]{ellsberg-urns.png}
\end{center}
\end{frame}
\begin{frame}\frametitle{A frame with a table}
Prisoner's dilemma
\begin{center}
\begin{tabular}{|c|c|c|}
\hline
& Cooperate & Defect \\
\hline
Cooperate & (3,3) & (0,5) \\
\hline
Defect & (5,0) & (1,1) \\
\hline
\end{tabular}
\end{center}
\end{frame}
\end{document}
A sample .tex of a simple document like coursework
\DocumentMetadata{
tagging=on,
pdfstandard={UA-2,A-4F},
lang=en,
tagging-setup={math/setup={mathml-AF,mathml-SE}},
}
\documentclass{article}
\newtheorem{definition}{Definition}
\newtheorem{theorem}{Theorem}
\usepackage{unicode-math} %some suggest this produces better mathml
\usepackage{amsopn}
\tagpdfsetup{table/header-rows = 1}
\tagpdfsetup{math/alt/use} %this is required to get a green blackboard ally score, but enables an out-dated accesibiliy approach: tagging math with alt text.
\begin{document}
\section{Question A1}
What model of decision making under uncertainty is represented by the following formula?
\[U(p)=\frac{\sum_{i=1}^n \omega_i p_i u(x_i)}{\sum_{i=1}^n \omega_i p_i}\]
\section{Question A2}
Consider the Prisoner's Dilemma, where the payoffs are given by the following table
\begin{center}
\begin{tabular}{c|c|c|}
& Cooperate & Defect \\
\hline
Cooperate & (3,3) & (0,5) \\
\hline
Defect & (5,0) & (1,1) \\
\hline
\end{tabular}
\end{center}
Find the Nash equilibrium of this game.
\end{document}