The Importance Of The Human Computer Interaction Computer Science Essay

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In recent years, the internet and the use of websites has become widespread by many users with disabilities in particular people who are blind or visually impaired. The Human-Computer interaction (HCI) has become an important subject of research in the last few years. It aims to design interactive systems and websites that are accessible to all. In 1990 the ease with which people with disabilities could access the web arose as an important issue. The US Government enforced legal action (Section 508) with The Web Accessibility Initiative (WAI) to increase accessibility to websites for blind people. Legislative action coupled with a greater awareness of the needs and requirements of those with visual impairments will play a crucial part in improving their quality of lives.

The majority of websites are inaccessible to people with disabilities such as blindness while the number of users who are totally blind has increased. However, tools and guidelines are available on some websites to allow access for employees, students or customers who suffer from visual impairment or total blindness. Such tools include screen readers which can transform the information on the screen into Braille and read the text aloud. However, some complex documents such as Flash or Java script remain inaccessible even when using a screen reader. It is clearly of rising importance that information should be made more accessible for people who have vision related disabilities. Software which helps to serve this purpose such as screen reader should be considered more ubiquitously by website designers so as not to exclude blind people from their subject base.

For all their advantages, screen reader systems cannot always guarantee clear understanding for visually impaired internet users. It is not always straightforward for them to find the information they want quickly and efficiently. A screen reader is a piece of software which converts the text on a page into spoken word via a speech synthesizer. It also converts written text into a Braille display which allows those suffering from blindness or vision impairments to interpret the text.

It can scan a computer screen for text and then audibly read the text content to help the user hear, and therefore understand, the text. However it is not currently available to read images, graphics, videos and PDF documents.

The advantages are obvious, but there are several problems which can occur when using a screen reader. First of all, a major problem can occur when navigating from link to link as this can result in loss of text on the page. Use of the 'Back' and 'Next' keys can cause confusion as the screen reader has to read out everything before proceeding.

In addition the users may find it difficult to recognize which link they have arrived at when they attempt to access a website. They will be forced to scan the text by checking every word on the page in order to try and recognize whether it is the page they require. The best solution would be if each link could be marked in some way so that the user can navigate their way between links with ease.

Secondly, a significant problem is that some pages have too much information and details such as frames or links. Such information may be irrelevant to the user but the screen reader has to read out all of the information on the page. The best way to solve this problem would be to arrange the content of the page in a hierarchical structure so as to prioritise the information. Any unnecessary adverts or irrelevant information would subsequently be placed at the end of the page and wouldn't cause such a great interruption to the main body of the text.

Thirdly, there is no doubt that visually impaired users have difficulty recognizing and finding non-text such as photos and graphics. Images on a webpage which provide additional information to the user subsequently require 'Alt-Text'. Without this tool the Screen reader is unable to process images and consequently ignores any text or messages within (See (Figure 1.1)). The result is that users who can't see the screen will only have limited access to information on a web page. They may miss out on crucial information contained in charts, tables or graphs.

Image is without Alt-Text or description

( (Figure 1.1)

The Alt-text tool allows the screen reader to decipher the text within the image and hear an audible explanation. If a website is equipped with this function then the user can listen to a vocal description by clicking on or hovering over the images.

It is evident that those who are totally blind can have problems with navigating web frames if they lack any sort of description. In this way, blind users would also benefit from the input of descriptive frames within search engines. Search engines can make a screen reader present very confusing information due to the multiple links and unfinished sentences on one page. In this way extra descriptive devices would address this issue. It has also been found that a monitor can be very useful and time saving accompaniment to a Screen reader.

Just as images can be tricky for a Screen reader to decipher, tables of information can also cause difficulties since the information may not make sense when read out loud. To avoid such confusion, simple tables can be explained if they incorporate HTML elements. Row and column headers, mark-up indicating sub-headings, and groups of columns and rows allow the data to be explained. If the table is particularly complex, additional text descriptions may be required.

Unfortunately, many web pages are written in non-valid HTML language which can be difficult to interpret since it is written for a specific browser. For instance, many screen readers are able to navigate through headings of a web document. However, the functionality can be lost if the headings are not defined through HTML. This problem can be solved if the web page uses valid HTML code and W3C HTML validation. Pages can then be checked for their accessibility by the designer and problems addressed should they arise.

It appears that websites with multimedia content such as 'YouTube' have become very popular for blind users. However, this is not without its' difficulties. Software controls limit the amount of audio-related multimedia which Screen readers can convert. Also, many pages require the use of a button or mouse to play a multimedia piece which requires hand-eye coordination and they frequently do not provide alternative text.

Furthermore, whilst blind users can normally rely on hearing speech from their Screen reader, the sound of the media can sometimes mask it. There is usually only one button to control volume so it is difficult to distinguish the two sounds.

Moreover, another important issue with screen reader technology is the inability to control dynamically changing content. A solution to both of these problem would be for the visually impaired user to have the ability to control the audio by pressing play ,stop etc. and mute the volume. It can also be useful to provide metadata function which can work alongside a screen reader. It can be very useful for an audio description function to support movies on the internet with a text format.

There are ethical and legal guidelines in place to ensure services are accessible to visually impaired users, particularly business or E-commerce websites. For example, some airline companies provide services online such as flight bookings and reservations which is subject to an Act. Legislation has played an important role to ensure that websites are accessible for users with disabilities. However many countries still do not have legislation to enforce such systems. For example, there is no legislation in Saudi Arabia that helps blind people access the internet.

The Disability Discrimination Act (DDA) and other legislations hope to encourage organizations to take responsible steps towards assisting those with disabilities and ensuring their sites are accessible to all. For example, The Royal National institute for Blind (RNIB) and Disability Rights Commission (DRC) are recommended by the DDA as having accessible websites. In addition the World Wide Web Consortium (W3C) and the Web Accessibility Initiative (WAI) are validating their sites for accessibility. IBM provides a new technology called 'aDesigner' which tests the accessibility of web pages.

Such action and guidelines can help the designer of a website make their pages accessible to all, test their site for accessibility and resolve any problems. The designer thus has an important role to play because if they understand the problems and requirements for visually impaired users, they can work with software developers to add new functions and develop websites which are as easy to use as possible.

In summary, more blind people use the internet than ever before and as a result, accessibility needs to be improved. Ethical and legal guidelines have helped to illustrate the problem but there is still room for technological advancement. Screen readers are the most useful aid at present although they have their limitations such as their inability to describe images, decipher multimedia content and navigate efficiently between links. Solutions have been suggested which include the hierarchical arrangement of information on a web page, link navigation markers, wider applicability of 'Alt-Text' and improved audio controls. Ultimately, the more aware website designers are of the needs and requirements of those with blindness or visual impairments, the better equipped they will be to increase accessibility for such users.