Principles For User Interface Design Computer Science Essay

Published Date: 02 Nov 2017

INTERACTION DESIGN

Nowadays almost everything has an interface that allows people communicate with systems. Raskin (2000) has defined interface as the medium that people interact with products through it and lets users to achieve their goals. Designing interface should be addressed properly with a high quality with taking usability principle in consideration. What is meant by that interface should be easy to learn by all people of all ages and be used easily by disability users. According to the assignment this essay will discuss the user interface(UI) with TV setup.

Principles for User Interface Design

Principles make smoother the design of the UI for a new application, but principles are also loaded with implicit assumptions with regard to the application domain, the context of use, and the user characteristics and goals. There are generic (e.g. "know the user") and more specific (e.g. "use red for urgent items") principles that address the multitude of issues associated with UI design, such as screen design, user needs and performance, input device, etc (Nielsen 1994, p.91). It has been argued that most UI design principles are catholic and apply to many categories of interactive applications, but there are might be exceptions in new usage paradigms (Nielsen 1990).

It has been argued that people spend most of their leisure time trying to moderate their moods. Daniel Goleman (1995, p.57) said that ‘managing our emotions is something of a full-time job much of what we do especially in our free time is an attempt to manage mood. Everything from reading a novel or watching television to the activities and the companions we choose can be a way to make ourselves feel better. The art of soothing ourselves is a fundamental life skill.’ Television is an information and entertainment medium that has traditionally.

occupied the largest share of domestic leisure time (Zillmann 2000). Television entertainment is a multidimensional construct that cannot be measured as such, but consists of several parameters that could be measured (Vorderer 2001). For example, Reeves and Nass (1996) assert that a mediated experience elicits an emotional response, which is partly valence (pleasure) and partly arousal. There are also additional elaborate models of the uses and gratifications when watching TV (Lee and Lee 1995, Rubin 1983). Therefore, the UI of an TV application could be conceptualized as an additional to channel changing and program selection means to moderate the mood of the TV viewer.

In order to watch television, viewers have to use a number of equipment (hardwares and softwares)such as DVD player, Video recorder, remote, cable box etc. that can sometimes be difficult to use for people with sensory or physical disabilities. It is for example difficult for a person with visual impairments to handle a remote control where the buttons are not clearly labelled or to read-screen text. Other users with physical disabilities may need special remote controls that are easy to hold. People with cognitive impairment need equipment that is easy to set-up and easy to use. Finally, people with sensory impairments will need equipments and softwares that are able to handle captions, audio-description or sign-language tracks when they are broadcast.

Equipments:

System setup

Although some people will have help available to help them during the initial installation , set-up and continued use of their equipment, others won’t. The complexities of connecting new equipment, tuning in channels and setting the required display preferences can present a real barrier to use for almost all consumers, but especially for people with sensory, mobility, intellectual or cognitive impairments. Figuring out which cable connects to which socket, fitting the cables, going through the set-up sequence, finding options and troubleshooting problems can be difficult and confusing. People without impairments may also find these tasks challenging, particularly those who are not used to new technologies. The less complicated the installation, set-up and use is the less likely users are to encounter problems that require additional customer support. Even when customer support is available, by phone for example, it can be difficult or impossible for some users to follow the prescribed steps.

Remote Controls

Remote controls used for operating television equipment can present particular difficulties for people with limited experience in using technology, restricted hand control or strength (prevalent among older users), restricted vision or difficulty reading or understanding words or symbols. Some of the new remote controls these days are purely touch screen sensitive and thereby inaccessible to people with sight loss.

The decreasing size of remote controls means small keys and small labels that people with visual disabilities find inaccessible. Some people are unable to distinguish between certain colour combinations used on keypads.Hearing impaired users cannot identify commands or controls that require hearing, so visual or tactile feedback when keys are pressed would be recommended.Some current remote controls have a huge number of keys for various functions. Those with cognitive impairments may have particular difficulty in learning the function of so many keys.

Due to reduced mobility and manual dexterity lifting and carrying a remote control or pressing small keys may prove difficult for those with physical impairments.

http://www.cardiac-eu.org/guidelines/images/elderly_remote.jpg

Elderly people often experience changes in vision, hearing, dexterity and understanding as they age, therefore they may encounter issues with small buttons and labels, identifiying the function of keys and holding the remote control unit. (Cardiac Project, 2009, Guidelines on remote controls)

Set top boxes

All receivers which decode the broadcast signal and output it to a television display need to be accessible. This is irrespective of whether they are integrated into the television or external to it, in the form of a set top box. Digital set-top boxes offer access to a wealth of information, entertainment and services via electronic program guides (EPGs), which require users to scroll through long lists of on-screen text and graphics to view choices and select a programme or service. The latest generation of digital set-top boxes offer EPGs that provide detailed information about programmes, the ability to set parental controls, and the ability to programme channel selections for future viewing. However, since most of the information on the EPG is of graphical nature, it is completely inaccessible to a blind person and extremely hard to follow for a partially sighted person. The more graphical the interface, the harder it is for a user who is blind or partially sighted to use it. (WBU User Requirements for Television Receiving Equipment 2011[Volume 1])

Digital Television [DTV]

DTV is the transmission of audio and video by digital

signals, incontrast to the analogue signals used by analogue television.

It supports the transmission of many more channels and also

access services such as audio description and subtitles. (WBU User Requirements for Television Receiving Equipment 2011[Volume 1])

Games consoles and personal computers with television tuners

The inclusion of television tuners within personal computers or

game consoles makes it possible for these devices to receive and

display television signals. The user interface requirements in

this document are also, in principle, applicable to these other devices. (WBU User Requirements for Television Receiving Equipment 2011[Volume 1])

User Requirements:

System setup

Full user guide and the quick start guide must be available, on request, in alternative formats – Braille, Large Print, Audio and accessible online formats. Information presented using diagrams and screen shots must also be available within the text instructions. The instructions must provide information about the accessibility features of the product and how to access audio description. On-screen information may also be provided, in addition to the printed manual. Receivers must carry out the full tuning sequence automatically following initial powering on once the receiver is connected to a display, a power source, or service platform [terrestrial, cable, satellite]. (WBU User Requirements for Television Receiving Equipment 2011[Volume 1])

On-screen displays

Adaptable fonts, changeable colours, simple uncluttered layout with zoom functions are all attributes that can transform a completely inaccessible on-screen display into a more usable product for blind and partially sighted viewers. However, lack of demand in the mainstream market has so far prevented equipment manufacturers looking into or providing features that will support the needs of blind and partially sighted people. (WBU User Requirements for Television Receiving Equipment 2011[Volume 1])

Remote Controls

Keys

· Include basic keys for power on/off, volume control, mute, channel entry and channel up/down

· Include accessibility keys e.g., for turning on digital subtitles and audio description

· Keys should be well separated with generous spacing between them (at least 50% of the width of the key)

· Keys should be large and differentiable by shape, size or texture

· Distinct shapes must correspond to the icons on the screen

· A raised tactile dot should be placed on the number '5' key without decreasing legibility of the visual marking

· Provide tactual and audible feedback when a key is activated

· Keys should be prioritised for inclusion on the remote control

· The keys should be logically grouped

· Provide pre-programmable keys for frequent functions

· The keys should be placed in an intuitive position for single handed operation

· The system must be error tolerant by providing a clear unambiguous key that permits the user to go back a step

· Position keys in a way that is consistent with functions, e.g., position the channel up key above the channel down key

· Keys should be operated independently avoiding double key pressing

Labelling

· Text and symbol labels should be clear, legible using an appropriate typeface and contrasted to the colour of the keys or background

· Labels should be done in the maximum print size possible

· Labelling should be durable and not rub off

· Labels should be intuitive and standardised

Touchscreens

· Graphical symbols (such as icons) should be accompanied by text

· An inactive space should be provided around each target

Physical characteristics and operation

· The remote control has a fixed hand strap

· The remote control has a textured grip

· The remote control should be easy to hold by someone with a weak grip

· There should not be parts which can easily come off

· There should be consistent design of the user interface adhering to the relevant standards whenever possible

· The remote control should be easy to operate on flat surfaces

· The remote control should be easy to operate one-handed

· The weight should be low if the users include children and older people. For interactive television applications, the user may need to hold the remote control for prolonged periods

· The directional properties of the infra-red beam should be wide so that someone with poor manual dexterity does not lose signal

· The remote control contains an audible or visual device that is activated from a base unit for easy location

Batteries

· Access to the battery compartment should be straightforward

· Battery insertion should be simple

Instruction manuals

· Use simple clear concise language

· Have a table of contents and a good index

· Be task orientated

· Provide alternate formats. (e.g. audio tape, large print)

· Use a typeface with good legibility

· Information contained in pictures should also be explained in the text

· Provide information on what to do if the remote control does not work correctly, or the user is unable to understand the instructions (e.g. a telephone help number)

  (Cardiac Project, 2009)

Some remote controls have a combination of the touchscreen and "hard" (traditional) buttons. These kind of remote controls can be used by blind people as well.

http://www.cardiac-eu.org/guidelines/images/touchscreen_remotes.jpg

Text-to-Speech [TTS]

TTS is automated verbal generation of elements presented on-screen [graphics, text, icons etc] in simulated human speech. A system used for this purpose is called a speech synthesiser and can be implemented in software or hardware. The user requirements for TTS are as follows:

An audio prompt must be provided at start-up that instructs the user how to enable TTS features.

The user must be able to activate or de-activate TTS as per need.

A single button on the remote control must be assigned at start-up to toggle the enabled / disabled setting.

The user must be given the control to increase or decrease the volume of TTS relative to the broadcast level. A number of factors could influence the user's decision to change the volume e.g. hearing ability of the user, distance from the product, ambient sounds etc.

The user should be able to adjust the speed of the TTS audio and other characteristics such pitch and TTS voice type.

The TTS should be available in different languages. Where there is receiver UI language that is not supported by TTS, then the user must be informed in some way before changing the UI language. (WBU User Requirements for Television Receiving Equipment 2011[Volume 1])

Parental lock

Users must be able to lock access to certain channels depending on the content being broadcast on the channel. This is only in cases where this feature, parental lock, has been made available on the system. (WBU User Requirements for Television Receiving Equipment

2011[Volume 1])

DVR

Clear indication must appear on-screen accompanied by an

audible signal [e.g. beep] when recording is initiated or stopped on a current event. DVR and On-demand services must also support recording and playback of audio description. When the hard disk of the DVR is almost full a warning message may be displayed on the screen whenever a recording starts or a new recording is programmed. This message may also be available in TTS. (WBU User Requirements for Television Receiving Equipment 2011[Volume 1])

Spoken subtitles

Programmes originating in foreign languages are often subtitled in the official or main language of the broadcasting country. In countries with a large number of non-native speakers or countries with more than one official or language, programmes may very often be subtitled in other commonly used languages. Viewers with sight loss will need to be able to access their own language subtitles using text to speech.(WBU User Requirements for Television Receiving Equipment 2011[Volume 1])

DTV

DTV receivers should be designed using universal design principles such that they do not create any access barrier for people with functional diversity. The user requirements in this section are applicable across the number of interactive services that area available via the television equipment these days such as internet television, IPTV, red button services, catch-up services.(WBU User Requirements for Television Receiving Equipment 2011[Volume 1])

Internet Television and IPTV

Internet television and IPTV are relatively new platforms for viewing television content that are fast gaining popularity and due to improvements in internet speeds, they are likely to become more and more popular. Internet television (sometimes known as online television) is a television service distributed via the internet. It allows the viewers to choose programmes that they want to watch from an archive of programs or from a channel directory. Internet Protocol television [IPTV] is a system through which television services are delivered using the internet and broadband internet access networks, instead of being delivered through traditional radio frequency broadcast or satellite or cable television.

Internet Protocol Television [IPTV]: IPTV services can be grouped into 3 main categories:

Live television, with or without interactivity linked to the television programme in progress;

Time-shifted programming and catch-up television;

Video on demand (VOD): browse a catalogue of videos

Watching content over Internet Protocol Television [IPTV]

involves watching content on a system that has a browser and

an internet connection. It is advisable to use User Interface

Web Browser Guidelines where content is delivered through a

web browser. These guidelines identify characteristics that

would provide a more adaptable user interface to allow users, not

only those with disabilities, to have a much greater selection in

what suits them most. (WBU User Requirements for Television Receiving Equipment 2011[Volume 1])