Accessible equations – by Dave Smith, School of Mathematics

There is a divide in the academic world between those for whom equations and mathematical expressions are their primary tools, and everyone else! Pure and applied mathematicians, computer scientists, physicists and many computational biologists (for the purposes of this blog post I will refer to all of us as mathematicians for short) typically find that widely-used tools such as Microsoft Word and Powerpoint are unsatisfying for the preparation of mathematics. Their main drawbacks are the combination of a clunky point-and-click interface with (to the experienced eye) substandard aesthetics. The alternative system, still relatively known outside of quantitative disciplines, is the typesetting language LaTeX (pronounced ‘Lay-Tech’ or possibly ‘Lah-Tech’) which was mainly developed in the 1970s and 80s. LaTeX enables the production of professional-quality printed documents with equations that most mathematicians consider rather beautiful; it is no surprise therefore that the vast majority of us produce all of our lecture notes and other course materials (handouts, exercises, slides and even examinations) in LaTeX. Typically the implementation that is used is ‘PDFLaTeX’, which converts LaTeX ‘source code’ into a PDF file that can be viewed electronically or printed. LaTeX has undoubtedly revolutionised mathematical publishing, and has also influenced the development of HTML (hypertext markup language), the basis for the web.

One of the great appeals of PDFLaTeX is that it gives us complete control over the visual layout. However, therein lies a weakness – not everyone consumes lecture material visually, and not all who do see in the same way. The most powerful example of this diversity is the use of screenreaders by blind and visually-impaired students. Equations appearing in PDF files produced by LaTeX are completely unintelligible to a screenreader. A workaround for this difficulty (used with success in the School of Mathematics) involves providing the LaTeX source files so that the code itself can be interpreted – ‘backslashes, curly brackets and all’ by a screenreader. This is a workable solution – and perhaps the best that can be expected in a short timeframe – but wouldn’t it be preferable if the core set of notes were suitable to be adapted by students to their varying needs? Other examples of how materials may need to be ‘consumed’ differently include the use of large print by students with visual impairments, or the use of sans-serif fonts and coloured backgrounds by students with dyslexia. Special materials can be printed out on request, but wouldn’t it be better if students could simply enlarge text, or experiment with changing the font or background to see what works best for them? The issue of how we consume reading material is most acutely relevant to those with visual impairment, however across all of the academic community we now view content across a range of devices, from monitors to laptops to tablets and phones, all of which require text to be able to resize and reflow according to the dimensions of the screen. We wouldn’t expect the Guardian online (or indeed the Big Conversation blog) to comes as a downloadable PDF. It seems reasonable that students should have similar expections of course materials.

HTML-based materials by contrast provide an excellent and up-to-date way to deliver device-friendly, resizable and reformattable content, along with the other advantages of web-based materials (particularly interactivity). The University’s online learning environment Canvas is a user-friendly platform for colleagues unfamilar with HTML code to prepare webpages. But what about mathematics? The best solution I am aware of involves integrating the old and the new: LaTeX expressions – which can be included by enclosing within the symbols \( and \) – within an HTML web page. LaTeX expressions can then be interpreted into mathematics through the online service MathJax, a javascript engine developed by the American Mathematical Society and Society for Industrial and Applied Mathematics. MathJax can be included in a webpage by adding a code snippet to the start of the HTML file; in Canvas this is done automatically. The result is mathematical expressions that look beautiful but more importantly are then available as MathML for the use of screenreaders. Having prepared materials in this way one no longer needs to anticipate all of the possible needs of current or future students – the power is with the student to manipulate the content appropriate to their needs. An example Canvas-LaTeX page is available at this link.

For the lecturer, converting a set of LaTeX notes to ‘Canvas-LaTeX’ or ‘HTML-LaTeX’ is essentially an task of cutting-and-pasting and then modifying commands such as section headings and figures – something that can be accomplished in a few hours for a 20 credit lecture course. Therefore there is a great opportunity to bring our lecture notes into the 21^st Century, retaining many of the advantages of LaTeX along with much greater accessibility. This change may require a shift in how we view course materials – our job is to provide content (text and equations), but we need to accept that our control over their precise visual appearance is a luxury which does not meet the needs of blind, visually-impaired or dyslexic students.