Monthly Archives: April 2010

Accessibility Equals Flexibility

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Flexibility is a Benefit of Accessibility

Flexibility is a Benefit of Accessibility

Ask any well informed Web developer to rate how important Web accessibility is, and I’d expect most to rank it high. Ask them why, and I’d expect most to talk about disabled users, altruism, and the law. An enlightened few may talk about the business case, or expand on the many technical advantages of making their sites accessible. As a professional developer you’ll know that many disabled users consider the Web to be a primary source for information, employment and entertainment. Indeed, from questioning and contact with many disabled users I have discovered that the importance of the Web cannot be under-estimated.

‘For me being online is everything. Its my hi-fi, my source of income, my supermarket, my telephone. Its my way in.’

This quote, taken from a blind user, sums up the sentiments I experience when talking with many disabled users, and drives home the importance of Web accessibility in the context of independent living. Indeed, by making sites accessible we help people live more productive lives, a view shared by Jef Raskin, creator of the Macintosh GUI for Apple Computer; inventor of SwyftWare via the Canon Cat; and author of ‘The Humane Interface’.

‘Humans are variously skilled and part of assuring the accessibility of technology consists of seeing that an individual’s skills match up well with the requirements for operating the technology. There are two components to this; training the human to accommodate the needs of the technology and designing the technology to meet the needs of the human. The better we do the latter, the less we need of the former.’

Indeed, it may surprise many designers and developers to know that when they are developing accessible code they are also, more then likely, developing aesthetically pleasing code too. But this shouldn’t be the most basic motivator for Web accessibility. Indeed, developers should also understand that accessible means mobile, or as Sears and Young put it, situational. The notion of the situationally-induced impairment, by which they do not mean an actual impairment of the person directly, but indirectly by the computational device or the environment in which it must be used. They point out that able-bodied individuals can be affected by both the environment in which they are working and the activities in which they are engaged, resulting in situationally-induced impairments. For example, an individual’s typing performance may decrease in a cold environment in which one’s finger does not bend easily due to extended exposure at low temperature, or the similarities between physical usability issues on both small-devices, such as a Mobile Telephone, Personal Digital Assistant, or any other hand-held device with a small keyboard and display, and accessible interaction scenarios. This means that by making your Web site accessible you can transfer accessibility solutions into the mobile and situational context. It’s a lot easier to make a Web page mobileOK if it is already accessible.

This support for the situational impairment, through flexibility, adaptability, and the ability to personalise the content, in other words transformable content, is important for access in developing regions too. Web use in developing regions is currently characterised by constrained operating modalities. Slow speed, low computational power, reduced bandwidth, compact keyboards, small screens, and limited power, all compound the problem of access and inclusion. In addition, interaction is sometimes without conventional written language and illiteracy is also a barrier to information and services. However, the benefits of Web technology are so great that the peoples of these regions often adopt resourceful methods of interaction and access sometimes repurposing Web resources so that they are put to a different use than for which they were intended. Understanding that content must be transformable also supports users at home who are conventionally excluded. Currently, the opportunities created by Web technologies are not enjoyed by the whole of society, indeed, there is a strong correlation between Web exclusion and social exclusion. There are significant and untapped opportunities to use the Web better on behalf of citizens, communities, and digitally disenfranchised groups. However to achieve inclusion, systems must be created seeing the human factor, not as an adjunct, but as a part of an integrated solution from the outset. We know that the multiplicity and ubiquity of devices and their interfaces are key to successful inclusion, households may very well have a games console or digital television, but no general purpose computer system. Being able to deliver content to any device, and support the users needs as opposed to the developers is key to making good Web resources which will be used, and which matter to real people.

Accessibility is not just about disability, if anything it is more about flexibility of mind at every level of the construction process form commissioning, through design and build, and on to evaluation. Accessibility accentuates good design and adaptability which helps future proof your sites against changes in guidelines, recommendations, and design. By making your sites accessible you also make them flexible.

Five Users Do Not Make a Study

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ResearchBlogging.org My recent conference and journal reviewing load seems to, increasingly, include research papers which justify their very small [user studies | post tests | summative evaluations] with Nielsen’s [1] “five user studies”. However, just as the proverbial ‘one swallow’ does not make a summer, so ‘five users’ do not make a usability study.

In reality, Nielsen never said that they do, without a lot of caveats and additional conditions needing to be met. However eager usability practitioners hooked upon this five user message as a way of justifying small studies, even when those small studies tested multiple and disjoint usability tasks. Even user studies that do not try to generalise their results need to make sure that the kinds of tasks performed are both limited and holistic. With these kinds of usability test Faulkner [2] demonstrates that the amount of usability errors uncovered could be as little as 55%:

It is widely assumed that 5 participants suffice for usability testing. In this study, 60 users were tested and random sets of 5 or more were sampled from the whole, to demonstrate the risks of using only 5 participants and the benefits of using more. Some of the randomly selected sets of 5 participants found 99% of the problems; other sets found only 55%. With 10 users, the lowest percentage of problems revealed by any one set was increased to 80%, and with 20 users, to 95%.

Faulkner (2003) Figure 1

Faulkner (2003) Figure 1

Indeed, as Figure 1 from [2] ably demonstrates, raising that number to fifteen gives a far higher chance of getting many more usability errors with a much lower level or variance.

So what does all this mean for the scientific researcher who wishes to uncover an understanding of ‘why’ and a certain level of generalisability to their findings? If you’re using qualitative methods, such as those found in anthropology and sociology, then the usual sample size (taking your aims into account) is normally between 10-20. The data from these participants are then coded to reveal trends within the data. For quantitative methods, such as those used in the Social Sciences and to some degree in Psychology, a statistical power test should guide you to an appropriate sample size. For True Experiments, such as those used in Experimental Psychology the sample size may vary widely but the variables under investigation must be reduced so that the confounding factors can be mitigated; indeed you may even like to delve into the finer details of the experiment, the quasi experiment, and the natural experiment at this point too.

Of course there are many other systems available to the human factors researcher to enable the uncovering of generalisable knowledge, such as those used in clinical trials and Epidemiology. However, the Computer Science facing human factors researcher has one advantage, normally we are pretty agnostic about the methods we use as long as they get the job done. With this in mind, it is my preference to use mixed-methods (hybrid methods) comprising each type of qualitative, quantitative, and experimental method in combination, and where appropriate. In this way, well designed mixed-method work employing a relatively small number of participants (in the order of 15 to 20, at a push; 30 to 50 would be better), can produce sound and generalisable understanding.

References

  1. Nielsen, J (1993). Usability engineering Book
  2. Faulkner L (2003). Beyond the five-user assumption: benefits of increased sample sizes in usability testing. Behavior research methods, instruments, & computers : a journal of the Psychonomic Society, Inc, 35 (3), 379-83 PMID: 14587545

Vote Labour

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Donate to Labour - Join the fight for Britain’s future. I once heard an eminent climatologists, when asked if global warming was responsible for current UK flooding, described the climate as the underlying nature and trend, while the weather was superficial and transitory. It seems to me that you can use these concepts to describe most things; an underlying nature coupled with a more superficial and transient nature. For example, in general my temperament may be good-natured (my underlying climate is even), however, I may become angry or disheartened for a short amount of time (my weather may become stormy for a short time). Of course the climatologist answered that the UK floods were short-term weather events and were not directly related to the underlying climate.

So what does this have to do with the impending UK elections? Well for me the climate of Labour is still firmly ‘Social Justice‘ and people and community first, while the Conservatives climate is still ‘Economic Liberalism‘ with companies and self interest first, people and community last; I won’t bother with the other parties as they are really just window dressing for this election.

So what does this have to do with Science and Education? Simply that Labour channel more money into science, education, and public services, than will the Tories. This advances society and thereby advances business and commerce.

People want financially sound business as this benefits them in their employment. However, a business first model advances organisations above people, wishing for most of the workforce to be less-educated and therefore mailable with just 10-15% or so to be at a more educated level; to achieve organisational leadership and competition. This stance encourages an artificial elitism in education (everyone should be educated to their own ability and not to the artificial requirements of business and commerce), and a scientific focus which only sees commercial outcomes as being useful or successful; I don’t need to make the point as to why this is a short sighted view.