Designing for Dyslexics: Part 1 of 3

Posted October 16th, 2006 by Mel Pedley

This is the first in a series of three articles examining the specific learning difficulty known as dyslexia and how web design can impact the ability of those afflicted to access information on web pages. The specific needs of dyslexics tend to be overshadowed by the more widely understood needs of the visually impaired. Unfortunately, design decisions that benefit the latter group tend create problems for the former. This is never more evident than in so-called “accessible” text only pages with their emphasis on high contrast and complete lack of images and colour.

One of the common problems that I have encountered is that many web developers have an incomplete understanding of dyslexia and the difficulties it creates. So let’s start by answering some questions about dyslexia and dispelling some common beliefs…

What is Dyslexia?

The word “dyslexia” can be broken down into two parts: “Dys” meaning poor and “lexia” meaning language. Thus dyslexics have difficulties with words. Current theories suggest that it is not a visual problem but a word decoding, or recognition deficit.

Our ability to recognise words is thought to be based upon two slightly different “memory skills” — phonetic memory and lexical memory. Dyslexics may have a good phonetic memory — as evidenced by their tendency to spell many words phonetically — but a very poor lexical memory.

Have you ever done a crossword and thought you had the answer to one of the clues but couldn’t quite remember how it’s spelled? Chances are that you scribbled it out on a piece of scrap paper to see which version “looked right.” That’s lexical memory in action.

Now imagine you didn’t have this built-in word recognition skill. Every written word you encountered might pose a new challenge as you struggled to decode it from scratch each time. It should be easy to see why tools like spell checkers and dictionaries aren’t of much use to a dyslexic. Chances are s/he can’t recognise the “correct spelling” even when it’s presented to them.

Isn’t “Dyslexia” Just About Reading?

No. It’s far more complex than that. Some confusion arises because the term “dyslexia” is often used simultaneously to mean a specific reading difficulty and a group of learning difficulties of which reading is one.

For example, someone might suffer from dysgraphia (writing), dysorthographia (spelling) and dyscalculia (numbers) as well as the common short-term memory problems but be able to read reasonably well. However they will probably be “labeled,” and think of themselves, as dyslexic as these are learning difficulties that are specific to written symbols of one type or another.

No two dyslexics demonstrate their disorder in the same manner. It can affect boys and girls equally, across all socioeconomic classes worldwide.

The British Dyslexia Association, BDA defines dyslexia as:

“A combination of abilities and difficulties that affect the learning process in one or more of reading, spelling and writing.

Accompanying weaknesses may be identified in areas of speed of processing, short-term memory, sequencing and organisation, auditory and/or visual perception, spoken language and motor skills. It is particularly related to mastering and using written language, which may include alphabetic, numeric and musical notation.” –British Dyslexia Association

Dyslexia is not a disease and cannot be cured — although strategies can be developed to work around it. It is a lifetime condition and is probably best envisaged as a particular form of brain wiring.

How many Dyslexics are there?

That’s difficult to estimate. Many dyslexics go through life without ever being diagnosed. Also the figures do vary from language to language.

For example, it is estimated that the UK has twice as many dyslexics as Italy. This is thought to be due to a difference in complexity between the two written languages. Written Italian has 33 graphemes (written symbols or groups of symbols) for only 25 phonemes (word sounds). Written English has 1,120 graphemes that can represent 40 phonemes. Thus the more complex the written language is, the greater the likely percentage of people who will have difficulty reading it.

As many as 1 in 10 people in the UK are dyslexic. Given that the current population of the UK is around 60.2 million according to National Statistics Online. This suggests that the number of dyslexics in the UK is likely to be in the region of 6 million.

The number of visually impaired people in the UK in April, 2005 was estimated at 1.7 million according to the Chartered Institute of Library and Information Professionals. So, in the UK, the number of dyslexics probably outnumber visually impaired users by at least 3:1.

Worldwide, it is likely that the number of dyslexics is likely to be equal to, if not significantly larger than, the number of visually impaired people.

What are the Effects of Dyslexia?

Well, it’s a lot more than just having problems reading words. For example, poor short-term memory and organisational skills will mean that site navigation and page organisation become more important.

Colour contrast, which I’ll discuss in more detail in a second article, can have a major impact on the readability of a page. A specific problem, sometimes referred to as “Scoptic Sensitivity Syndrome,” can make high contrast text difficult or impossible to read. The phrases I’ve heard most often are “the text keeps moving” or “the words seem to dance on the page.” But most dyslexics suffer from more than one specific difficulty to varying degrees. As a result, it’s difficult to find accurate figures as to how many suffer from any one specific issue.

What is generally accepted is that there are a number of factors inherent in web page design which, if not implemented sympathetically, can make page content difficult to process and induce rapid tiredness. This is likely to be made worse by the “eye-tiredness” that everyone suffers from when trying to read text on a screen. Dyslexics already have to expend a lot of effort in order to read at all. So they will tire far faster. An unsympathetic web page can be a recipe for extreme tiredness and cause frustration very quickly.

Many of the issues that affect dyslexics will be similar to anyone who is having to deal with tiredness — such as Chronic Fatigue Syndrome or exhaustion brought on by dealing with chronic pain.

Addressing these issues will not only reduce specific barriers for the above groups but will significantly enhance web page readability for all.

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