Human Computer Interface - Essay Example

CONTENTS Introduction2 Basic techniques for accessibility..4 Cascading Style Sheets...5 DDA Act...6 Conclusion...7 Introduction Human-Computer Interaction (HCI) is the study of how people devise, implement, and use interactive computer systems, and how computers influence individuals, organizations, as well as society. This covers not just the simplicity of computer use but fresh interaction techniques for sustaining user tasks, giving better access to information, and fashioning more potent forms of communication. HCI involves input and output devices as well as the techniques that use them. It also deals with how information is presented; how it is requested; how computer actions are monitored and controlled; all types of documentation, help, and training; the tools required to build, test, and assess user interfaces; and the procedures that developers follow when producing interfaces. The Internet has developed with tremendous rapidity over the years. Today, companies see the World Wide Web as a great tool to promote themselves. Here, the stress is characteristically given to building visually striking sites designed to impact the viewer. High-profile websites require great control over the presentation of the webpage and due to the competency of HTML and Cascading Style Sheets companies are delivering content their marketing deserves. However, as website designers produce what must be displayed in complete terms, people with disabilities are affected. For example, users with poor vision require the capacity to organize what size text can be available in their browser. This breaks up the design of the page and defeats the web designer's original aim. Generally, people do not have accessibility requirements. Thus, it is of no surprise that most designers are not trained in them. Also, interfaces implemented without allowing for accessibility needs are more impressive looking, and companies generally do not have an accessibility version of their website. Those organisations providing accessibility versions do it at extra cost by building a wholly separate user interface. Concomitant to the moral and commercial reasons for offering accessible websites, the Disability Discrimination Act defines a legal prerequisite in this regard that all companies must conform with. Therefore, to provide an accessible user interface is a must for all organisations; there is no other alternative in this regard. Today, users demand extremely effective and user-friendly interfaces; so developers are now realizing the crucial role that interfaces plays. According to surveys, 50% of the programming and design effort is dedicated to interface. Also, the human-computer interface is vital to the products' success in the marketplace, apart from the usefulness, safety, and enjoyment of using computer-based systems. There is considerable experiential evidence that using the processes and techniques developed by the HCI fraternity can radically decrease costs and increase output. One study reported savings through the deployment of usability engineering of $41,700 in a small-sized application used by about 23,000 marketing personnel, and $6,800,000 for a big-scale business application that was being used by 240,000 employees. Savings were credited to lesser task time, smaller number of errors, greatly reduced user disturbance, less burden on support staff, removal of training etc. [Nielsen 1]. A usability analysis of a projected workstation save a telephone company an amazing $2 million annually in operating costs [Gray 1]. A mathematical model founded on eleven studies shows that using software that has been tested through usability engineering can save $39,000, $613,000 and $8,200,000 for a small, medium and large project respectively. [Nielsen 2}]. Another study found that by estimating all the costs connected with usability engineering, benefits can go up to 5000 times the cost [Nielsen 2]. However, there are well known disasters that have come about from a lack of understanding of human-computer interface. The complex user interface of the Aegis tracking system was causative to the downing of an Iranian passenger plane. Problems with the interfaces of commercial and military airplane cockpits probably are the cause of many crashes. The Cali crash of December 1995 is a perspicuous example. Basic Techniques for Accessibility Even though building an accessible website is a lot more than just added alternate text elements for page imagery, it can enhance the website's usability for visitors to the site. The guidelines formed by the Web Content Accessibility Guidelines (WCAG) facilitate a website to be created in an accessible manner The following are a few tips. Give a text equivalent for all non-text elements using the 'alt attribute'. This should be deployed for animations and images as a minimum requirement. If colour is there to convey information, it should be made certain that the information can be seen without the use of colour. After all, over 50% of all men in this world suffer from some sort of color blindness. Use text on hyperlinks that can be understood when seen out of context - 'click here' usage should be avoided. Offer substitute content for scripts and plug-ins in case active features are inaccessible. Cascading Style Sheets (CSS) should be used to control font size, colour as well as other presentational effects. Use CSS to position items on the page if possible. Authenticate mark-up, use tools, guidelines and checklists. Use all browser types while testing and, if possible, with a group of people suffering from different types of disabilities. Guarantee a reliable structure of presentation and page layout. Cascading Style Sheets Cascading Style Sheets (CSS) is a web markup language, created by the World Wide Web Consortium (W3C). CSS goes together with HTML and gives users and developers greater control over the way pages are displayed. CSS facilitates separation from the appearance of a page (CSS) from its constitution and informational content (HTML). This is a particularly great idea as users access content by using a wide spectrum of devices and media. A document's presentation, therefore, should not be identical for one and all, but content and structure should be. Those with disabilities benefit from this approach, as they have greater control over how web pages are viewed. Users with low vision can make their own large-font, high-contrast style sheet and use the browser to supersede web pages' offered style sheets with a style that caters to their needs and preferences. There are at present two versions of CSS-CSS1 and CSS2. The CSS2, issued by the W3C in 1998, has great potential for improving convenience in that it facilitates media-specific style sheets, like aural style sheets and those for non-standard devices. Checkpoint 3.3, in the W3's Web Content Accessibility Guidelines (WCAG) 1.0, says, "Use style sheets to control layout and presentation". The subsequent checkpoint in WCAG 2.0, which is presently a working draft, is Guideline 1.3 and that says "Ensure that information, functionality, and structure are separable from presentation". WCAG 1.0 has been the cause of some misunderstanding on this topic, since it advocates using style sheets as noted above, but it also seems to dissuade the use of style sheets. "Organize documents so they may be read without style sheets. For example, when an HTML document is rendered without associated style sheets, it must still be possible to read the document," says Checkpoint 6.1. This checkpoint, however, should not be misconstrued as discouraging CSS. More accurately, the idea is to make use of CSS without your site becoming too dependent on CSS. Since users have the capability to supersede the author's specified style sheet, the web content may look entirely different for these users. Also, users viewing the page with older browsers, handheld computers, text-only browsers, wireless phones, or other technologies that do not quite support CSS can still access the content. DDA ACT The Disability Discrimination Act (DDA) has made it a transgression to discriminate against disabled people. "The Disability Discrimination Act makes it unlawful for a service provider to discriminate against a disabled person by refusing to provide any service which it provides to members of the public What services are affected by the Disability Discrimination Act An airline company provides a flight reservation and booking service to the public on its website. This is a provision of a service and is subject to the actFor people with visual impairments and hearing disabilities, the range of auxiliary aids or services which it might be reasonable to provide to ensure that services are accessible might include ... accessible websites." - Part III of the Disability Discrimination Act. It is widely accepted that the W3C accessibility guidelines can be employed to evaluate a website's accessibility and eventually it's conformity with the act. The W3C is an association that leads the web and provides three different levels of conformity. Priority 1 guidelines have to be adhered to, while priority 2 guidelines are the EU suggested levels of compliance. The Disability Discrimination Act 1995 - Word (the DDA), was came into force with the intention of systematically tackling the bias which disabled people face. On 1 October 1999, the DDA made it obligatory for websites to be accessible. Later, the Code of Practice was published on 27 May 2002. Generally speaking, the DDA makes it illegal to show favouritism against disabled people while recruiting people; provide services; or regarding education. Discrimination can happen in a couple of way, either by treating a disabled person unfavourably; and/or not being able to make "reasonable adjustments" so that disabled people can partake in education and employment and can make use of a service. The following is an example of an airline website cited to define a service outline. "An airline company provides a flight reservation and booking service to the public on its website. This is a provision of a service and is subject to the act." - Code of Practice 2.13 - 2.17 (p11-13) A disabled person can file a lawsuit against a website if it makes it impossible or difficult to get information and services. If the website has not made reasonable adjustments and cannot prove justification for the failure, then it is liable for justification and can be ordered by the court to alter the site apart from having to pay compensation. A useful mention is this context is a case brought against the Sydney Olympics Committee in 2000. The website owners had to part with 20,000 Australian dollars. In lay parlance, the DDA requires that websites make "reasonable adjustments" to their services to make certain that a person with a disability can use their services. This includes modifications to the website, and a spectrum of features not available via website, like a telephone serve. On February 27 2002, the Disability Rights Commission (DRC) made available a new draft of the Code of Practice. This Code of Practice is applicable to service providers and includes revision on websites. The Code of Practice that supplements the DDA is not an articulate statement of the law, but somewhat of a guide to service providers as to what the law is liable to be - and something that courts are required to take into consideration when taking into account issues that take place under the Act. Therefore even as it still cannot be said that there is a specific legal requirement under the UK's Disability Discrimination Act for websites to be made available in an accessible form the debate is getting stronger. Text-based Web pages Will DDA compliance result in future web pages being wholly text based The answer could just be yes. The text information related to a non-text element should ideally communicate the same information as its connected element. When an image points to an action, the action must be explained in the text. Generally, non-text elements requiring text descriptions are restricted to elements that provide information necessary for understanding of content or those used to assist navigation. Usually, web page authors make use of transparent graphics for spacing. Supplementing text description to these elements will bring about needless clutter for users of screen readers. Any image, audio clip, graphic, or other feature that communicates meaning through a picture or sound is a non-text element. Buttons, check boxes, pictures and fixed or streaming video and audio are illustrations. When audio presentations are obtainable on a multimedia web page, the audio segment must be titled. Audio being a non-text element, text equivalent must be provided if it is part of a multimedia presentation. There are several ways of giving textual information for it to be recognized by assistive technology devices. For example, the tag can accept an "alt" feature that will facilitate a web designer to include text that explains the picture directly in the tag. How does a text equivalent make image available Text content can be braille, synthesized speech, and visually-displayed text. These mechanisms each uses a different sense -- tactile for braille, ears for synthesized speech, and eyes for visually-displayed text. This makes the information available to groups having a variety of sensory and other disabilities. The text must convey the same function or use as the image. For example, consider a text equivalent for a scenic photograph of The Grand Canyon. If the point of the image is mostly that of adornment, then the text "Grand Canyon as dusk" might fulfil the required function. If the purpose is to convey some information, the corresponding text would be "Information about the Grand Canyon". If the text communicates the same function for the user with a disability as the image does for "normal" users, then it can be deemed a text equivalent. Not only with people with disabilities, but text can equivalents generally help all users - with or without disability - to use the web more efficiently. Web content developers must give text equivalents for images and multimedia content in general; however, it is the duty of user agents like browsers, screen readers, braille displays, etc. to present the information to the user. Non-text equivalents of text are important too. Icons, pre-recorded speech, video etc. can make documents available to people who have difficulty reading text. These include people with learning disabilities, cognitive disabilities, deafness et al. An auditory description is an illustration of a non-text equal of visual information. An auditory description benefits people who cannot view the visual information. Sighted and Blind Users Blindness involves a considerable, uncorrectable vision loss in both eyes. Many individuals who are blind use screen readers -- software capable of reading text on the monitor and outputting the information to a refreshable or a speech synthesizer. Also, there are text-based browsers like Lynx, or voice browsers that can be of help. Then there are rapid navigation strategies like tabbing through links on web pages rather than having to read every word on the page in succession. There are several barriers that blind people face on the web. They are images lacking alternative text; images that are not adequately explained; video without text or audio description; incomprehensible tables; frames lacking "NOFRAME" alternatives, or without meaningful names; poorly labelled forms; authoring tools without keyboard support for all commands; browsers and authoring tools lacking standard applications programmer interfaces for the functioning system they are found in; and non-standard document formats that may be complicated for their screen reader to understand. Sighted users suffer from instance poor acuity, tunnel vision, central field loss, and clouded vision. Some people with low vision have extra-large monitors, and amplify the size of system images and fonts. Others use screen enhancement software, while some have combinations of text and background colors, like bright yellow font on a black background. Sighted users may also encounter some problems on the on the web, including web pages with complete font sizes that have difficulty changing: web pages that are difficult to navigate when enlarged, owing to loss of surrounding context; web pages or images on web pages having poor contrast and which cannot be changed easily owing to user override of style sheets; text provided as images, which prevents wrapping to the following line when enlarged et al. There is software used by individuals that interprets what is displayed on a screen and directs it to either refreshable braille for tactile output or speech synthesis for audio output. Some screen readers use the document tree (i.e., the parsed document code) as their input. Text browsers like Lynx are a substitute to graphical user interface browsers. They can be used for blind people. Screen readers or voice browsers can generate speech synthesis and speech output. Those involve creation of digitized speech from text. For instance, for those people who cannot operate a mouse, one approach for quickly scanning through headers, links, list items, or other items on a Web page is to use the tab key. People using screen readers can tab through items on a page, as well as those using voice recognition. Conclusion Accessibility stands for a significant step towards independence for users suffering from some sort of a disability, as it can give quick, easy, low-cost access to information and services. Providing this means of communication can throw up a range of opportunities, including employment, entertainment and education, apart from offering the chance to take part in everyday activities that "normal" people take for granted, banking and shopping being examples. Accessibility aids an assortment of people with and without disabilities; everybody can benefit from an accessible website. Web pages that are produced keeping in mind a disabled audience will be pleasing to the eye, easy to maintain, fast loading, give information in a simple and direct way, can be navigated with stability, and will operate across a variety of rendering devices and browsers. With constant improvements in the usability of websites - comprehending the way people use websites, recognizing key tasks and information, finding information - there has been a stark reduction in support costs and the numbers of customers that are discard shopping baskets before the checkout. Accessibility improves on this, initially by helping to attract more customers to a site, and by generating an environment that offers a simple, instinctive method for buying goods and services. Many disabled people live on their computers. A computer is often a link to the outside world where a disabled person can carry out tasks equivalent to a non-disabled person. Looking after the disabled market will persuade users to spend money with a company. The number of disable people in UK is 15%, which amounts to about 9 million people. The yearly spending power in the UK is close to 40 billion, an amount that is being ignored by companies. References [Nielsen 1]: Jakob Nielsen, Usability Engineering, Boston: Academic Press, 1993J. [Nielsen 2]: Nielsen and T. K. Landauer, "A Mathematical Model of the Finding of Usability Problems," Proceedings INTERCHI'93: Human Factors in Computing Systems, Amsterdam, The Netherlands, Apr, 1993, pp. 206-213. [Gray 1]: Gray, W. D., John, B. E., and Atwood, M. E. "Project Ernestine: Validating a GOMS analysis for predicting and explaining real-world task performance." Human-Computer Interaction, 8, 1993, pp. 237-309. Internet Used http://www.apple.com http://www.icdri.org/index.html http://www.washington.edu http://www.indrum.com http://www.webcredible.co.uk http://en.wikipedia.org http://www.w3.org http://www.cs.brown.edu http://www.recipexperience.com . Read More