HCI (human-computer interaction).
HCI (human-computer interaction)
Human-computer interaction is a field concerned with the design, evaluation and implementation of interactive computing systems for human use.
It is a field concerned with many disciplines including computer graphics, the system part of computer science, operating systems, ergonomics, psychology, sociology and anthropology (interactions between technology, work, and organisation) and industrial design (interactive products).
There are several physical and psychological factors that can boost the effectiveness of human-computer interaction.
For effective interaction, comfort for the human is essential. Furniture should be comfortable and adjustable as poorly designed chairs are responsible for back trouble.
Lighting should be the appropriate intensity as well as being positioned appropriately to avoid casting shadows. Computer screens should be positioned away from light sources such as windows to avoid glare, and windows should have blinds to control the brightness of the room.
Psychological factors play a big role in human-computer interaction. Information is transported through the sense - Vision, hearing, touch, and movement.
The eye is less sensitive to blue than red or green light. There are much fewer shades of blue that the eye can distinguish between than red or green. Thus, important information should not be displayed in blue.
Techniques of highlighting such as brightness variation, blinking and colour coding should be used sparingly. Brightness variation should be limited to two levels, bold and normal, as other variations would be difficult to detect. Colour-blind users will be unable to distinguish between red and green. This concludes that an interface should not depend on being able to distinguish colours. Spacing is also important, full use should be made of the space available.
Sound is also an important tool, for example it can be executed as warning sounds in PC's or police cars. Humans react faster to sound ...
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Techniques of highlighting such as brightness variation, blinking and colour coding should be used sparingly. Brightness variation should be limited to two levels, bold and normal, as other variations would be difficult to detect. Colour-blind users will be unable to distinguish between red and green. This concludes that an interface should not depend on being able to distinguish colours. Spacing is also important, full use should be made of the space available.
Sound is also an important tool, for example it can be executed as warning sounds in PC's or police cars. Humans react faster to sound than sight, and can distinguish between an extensive ranges of sounds.
Touch can be important for blind, or deaf people and is an important part in keyboard and mouse design.
More simply human-computer interaction is the study of the joint performance of tasks by humans and machines; human capabilities to use machines; and the design, programming and implementation of interfaces.
Therefore the human-computer interface is the single most influential factor in human-computer interaction. An interface can create ease of communication for the human leading to a better response to the computer, as the computer is not intelligent and relies on the human to perform.
The increase in microcomputer usage has erected the need for user-friendly interfaces, for an increasing number of computer users whom most are not experienced. A good user interface should put user convenience paramount, it should be easy to learn and come to grips with, appealing to the eye, provide help for novice users, provide short-cuts for experts, provide helpful error messages, and use metaphors for ease and to aid memory.
When we think of a human-computer interface, a desktop PC is the first thing that comes to mind, however, a human-computer interface is not restricted to a home desktop PC. An ATM (Automated teller machine), a pilot's flight panel, and industrial processes such as the making of steel also use human-computer interfaces.
Therefore, many factors have to be taken into consideration when designing a human-computer interface, such as who will use the system, what tasks will be performed, and the environment in which the system will be used in (e.g. a touch screen may not be suitable for damp or humid conditions, a voice recognition system should not be used in a excessively noisy environment).
There are a number of interfaces presently available. These are the command line interface, menus, natural language, forms, dialogue boxes, and the graphical user interface (GUI).
The Human-computer interface usually consists of metaphors so that a user can associate commands with icons, such as documents for files, waste paper basket for recycle bin, and folders for directories.
Gui (graphical user interface) are user friendly, in the sense that they are more appealing to the eye and are easier to use than a command line interface. However, they occupy more memory, they need more space on disk, runs more slowly if there is complex graphics, and more time consuming for a experienced user.
The WIMP (windows, icons, menus, and pointing) interface originated from Xerox PARC Laboratories in the mid-1970s and was employed on the Apple Lisa and Macintosh computers. Currently the most recognised WIMP interface is used in the Microsoft Windows operating system
The WIMP interface has many advantages. It is easy to grasp and use, it is possible to switch between tasks (multi-tasking), and the use of icons speed up operations and commands.
The command line interface is an interface in which the user has to enter a command to obtain a response. The most well known command line interface is associated with MS/DOS. The command line interface is ideally suited for expert use, and is unsuitable for inexperienced users due to the fact that the command language must be learnt and remembered, and system interaction is restricted to the keyboard.
Natural language interface can understand plain English. This type of the interface is good in the fact that the user does not need to know ay command language, and it is flexible. However, the flaws are that the English has to be strictly grammatical English, and natural language is often too ambiguous for a computer, which could lead to many mistakes.
Another user-friendly interface is voice recognition system. This is particularly useful if the hands are occupied The voice recognition system is presently used in call handling systems, bank account enquires, reverse charge calls and reverse charge calls. The voice recognition interface can provide a list of options for the user to choose orally, or process whole sentences and displays them on the screen. The voice recognition interface does, however, require the user to train the computer to recognise its voice, is not completely accurate, and is an expensive technology.
