Accessibility 6: Align Left
You know the first ten seconds of the interview? How the handshake, meeting the eye, standing appropriately, being dressed for the part — all make a first impression that probably, you cannot undo?
When sighted people read a screen or a page, they have already had their first impression. They have started reading; they knew where to start. They know how many things they must read, on that screen as a whole.
If it is a list they are reading, before they even begin, they know how many items appear in that list. That unconscious knowledge affects the whole way you approach each piece of the text. Even your awareness that the text is a piece of some larger text, is part of the first, subliminal impression.
Code does for the non-visual reader what the first impression does for the sighted person. Code tells that reader’s screenreader to announce before they get to the text what kind of text it will be. Lists are coded up with list tags; headings have header tags.
Even when you get to the visual formatting, this is a principle that matters. Left-aligned text has a straight margin on the left side only — it has a jaggy margin to the right — which makes it easy to see where each line stops, and easier to know where to begin the next line.
Centred text is less difficult for sighted readers, who can take it in as a whole, but readers with low vision, small screens, or low cognitive processing speed, or other difficulties in reading, may not. Too little white space between one column and the next, or one line and the next, and a reader with dyslexia may find that their impression of one word, blurs into their impression of another.
Spacing was ‘leading’ in the old days of print, because blank, low-down ‘lead’ (actually an amalgam, not lead) was inserted between raised lead ‘types’ that were carved to be letters, in reverse, at the top. ‘Justification’, with straight margin both sides, was a matter of pride for printers, because leading had to be inserted between words, even letters, without being too obvious. It also saved money; it looked ‘finished’.
But it is not accessible!