Other important features of problems encountered by blind users

The problems encountered by blind users covered a wider range of types of problems than partially sighted and dyslexic users. Problems encountered by blind users were in 64 subcategories, while problems encountered by partially sighted users were in 54 categories, and in 43 for dyslexic users.

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4.2.2.1

The importance of search features to blind users

Among the problems listed in the subcategory “expected functionality not present”, it is noteworthy that a large amount of those problems were related to users expecting to have a search feature on websites. This is a very important consideration in favour of providing users with facilities to search for content on websites. The importance of search features to blind users can be justified by the considerable time it takes for them to browse through a website, due to the nature of their assistive technology based on speech. Being able to search for content instead of having to browser a website can significantly increase users’ performance. However, it is important that search features work correctly and do cover all content available in websites. Many problems in the subcategory “functionality does not work (as expected)” corresponded to issues where search features failed to find content that users were confident was on the website using what seemed to be correct keywords.

4.2.2.2

Importance of headings to blind users

It was clear from this study that headings play an important role in navigation to blind users, with as many as 8% of problems encountered by blind users being related to headings. This is in agreement with the survey results from WebAIM (2011), in which 57.2% of 1,245 screen-reader users reported to use headings as a first approach to navigating within web pages. In the present study, not having any headings on pages was listed among the fifteen most frequent types of problems, but had median severity rating 2 (minor).

4.2.2.3

Identifying link destinations properly

Although not the most severe, problems with unclear destination of links were the most frequent type of accessibility problem encountered by blind users, with more than 8% of the problems. Blind users are affected by different problems from other users when they attempt to identify the destination of a link. In this study, many problems were related to link destinations being identified by poorly labelled images or by link destinations that do not make sense on their own, without considering the context in which they are placed.

93 93 Some accessibility guidelines have suggested that it would be acceptable to have

link destinations that could be identifiable when placed in context (Caldwell et al. 2008), for example, a link identified as “read more” placed at the end of a paragraph with a summary of an article. However, more than 20% of the problems with unclear link destinations in the present study occurred with links that would make sense when placed in context. Many blind users used a feature in their screen readers that listed all links in a page, placed out of context.

4.2.2.4

Importance of content organisation to blind users

Inadequate organisation of content in web pages caused a substantial amount of problems to blind users in this study. As screen readers read content sequentially, the organisation of content can make it difficult for blind users to encounter the piece of information they wanted. The subcategory “irrelevant content before task content” alone accounted for more than 6% of all problems. Not all the problems were related to some classic web accessibility examples, where users find a navigation bar they have already read in previous pages before the content of a news article they want to read. Many problems were related to users finding advertisements and other irrelevant content that was not repeated in several pages before relevant content.

The subcategory “organisation of content is inconsistent with web conventions or common sense” also had a substantial number of problems. In problems in this subcategory, blind users also had to spend too much time scanning pages for content due to poor organisation of content.

4.2.2.5

Ineffective alternatives to CAPTCHAS and too little

time to complete forms

It is well-known that CAPTCHAS are a serious problem to blind users, since the images with distorted text do not have associated textual alternatives on purpose, to avoid that computers recognise it. The common solution to visual CAPTCHAs is the use of “audio-captchas”, where a distorted audio contains a sequence of letters, numbers or words that have to be recognised.

One website in this study implemented an audio-captcha with sound in a noisy background. All users that attempted to use the audio-captcha found it extremely difficult to use it, and only three users managed to complete this task after a number of

94 94 attempts that would be simply impractical in day-to-day activities. It is clear from the

results in this study that simply providing “audio-captchas” with noisy background sound is not always an effective solution to providing an alternative to the visual captchas.

The few users who managed to solve this “audio-captcha” were faced with a

message informing them that the system had timed out. They had been given only five minutes to try and solve the captcha.

4.2.2.6

Low severity of problems related to alternative texts

to images

Assigning textual alternatives to images became a flagship and one of the most well-known issues of accessibility of websites to blind users. It was an unexpected result to find that those problems did not have a high severity rating from users. The subcategories related to this specific problems had median severity rating 2 (minor), including “link destination is not clear”, that had 36 problem instances related to poorly labelled images to identify a link destination. It could be that blind users may have become accustomed to encountering those problems and learned to ignore them.

Unless an image was crucial to users’ tasks, blind users tended not to rate those problems so severely. However, it is worth noting that this is a very frequent problem encountered by users, and it can become a serious annoyance to users, even when they are not necessarily interested in the images (such as in adverts), but have to listen to non-sense content from their screen readers.

It is also noteworthy that problems with images without proper labels were more frequent than problems with images with no textual alternatives at all.

4.2.2.7

Lower aversion to Flash

It seems that there are few problems with aversion to Flash from users. Although many specific problems were encountered in Flash applications, only 3 blind users reported problems where they had an aversion to Flash and wanted a separate alternative to it. That may indicate that some improvement has been made in the accessibility of Flash applications and its support from screen readers. However, it should also be noted that a substantial amount of specific problems were encountered with the lack of or poor labels of Flash elements, inability to use Flash interface

95 95 components with the keyboard and other issues that should be addressed by

developers when using Flash technologies.

Although few blind users had a total aversion to Flash, it is very important to highlight the importance of having special care to design interactive components that are usable by blind and other disabled users.

4.2.2.8

Dissatisfaction with text in PDF format

Unlike Flash, this study revealed that some blind users still have a dissatisfaction with text in PDF format, despite efforts to make files in this format more accessible. In 17 occasions, blind users reported problems with text being only available in PDF. Some of these problems occurred with PDF files that had accessibility features

implemented. However, users still reported that they wanted an alternative in a different format. This could be due to repeated problems encountered previously by these users with PDFs, which made them have an aversion to files in this format. It could also be due to blind users still not being used to using different strategies to use PDF document from those they use with regular HTML content.

4.3 Accessibility problems encountered by partially sighted