User Interface Development

Human Interface Devices

User Technology

User Groups

Accessibility

Interface Devices - The Mouse

The Mouse is the most used and recognised user interface device.Since it’s inception, it revolutionised the way that users couldinteract with screen design.

Formerly, interaction was only through the keyboard, but withthe development of the WIMP system (Windows, Icons, Mouse,Pointing device) there was now easier access and increased levelsof interactivity to work with.

This simple method of moving around on screen, selecting andscrolling, gave the user more freedom and more speed to reactwith the design environment.

Interface Devices - The Mouse

The Mouse does have some negative points:

• The traditional roller ball mouse meant lack of friction on a smooth desk means that it requires a special mat to run on.• This has now been superceded with the Infra red mouse, however this mouse does not operate on a glass table.• The mouse is fine for general use in accessing menus but not specialist tasks such as drawing.• Dirt is easily trapped on the underside of the mouse causing impaired use.

The Trackball

The trackball is basically an upside down mouse which isoperated using fingers, thumb or palm of the hand to move thecursor around the screen.

Commonly used on CAD workstations, pc’s where there islimited work space and air traffic control rooms with use for radars.Sometimes used on ships and submarines in conjunction with sonarequipment.

Early arcade games used trackballs.

The Touch Pad

The touch pad is more commonly found on a laptop fornavigation around the screen. It replaces the need for a mouseand usually comes with a clickable area. They are sometimesawkward and clumsy to use.

Operable using the forefinger moved across the area on the touchpad, they are useful for working while traveling without theaddition of any extra peripheral cables.

The Graphics Tablet

The graphics tablet is designed to be used specifically as a digitaldrawing tool. It comes with a stylus pen which allows precision inimage making. Can be used to trace pre drawn freehand images.Pressure sensitive tablets are the most intuitive.

The tablet part comes in varying sizes from A6 to A3 and Wacomtend to be the leaders in this technology. These have developedinto tablet pc’s where you draw directly onto the viewable screen.

The Gaming Control

Games controllers first began as joysticks developed with the useof gaming in mind. Also known as a gamepad or joypad they arecontrolled held in the palms of hands using thumbs and forefingers.

Manufacturers have developed these systems depending on thedemands and type of games played.

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Touch Screen Display

Touch screen displays allow the user to input information by touching the appropriate sensitised area.

They are relatively easy to use and offer the user a greater senseof interacting with the multimedia application.

Frequently in use as electronic kiosk designs in museums, artgalleries and at information points.

Modern screens now allow the facility of “mouse over events”,being more flexible and detecting the difference between thefinger on and the button push. Extend to screen keyboard,dragging and sliding.

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Touch Screen Display

Drawbacks with touch screen devices - Not suitable for domestic PC monitor use as the extended armposition is more tiring.

Buttons have to be larger and more spread out to allow for largerdimensions of the finger. Button “hit” area must be larger,therefore altering design of interface.

Button changes on “mouse events” are obscured by the finger.similar symbols showing that a button has been accessed mustappear around the side, taking more space in the design.

Drop down menus are more problematic in these designs.

Foot Mouse

Completely foot operated, it eliminates the wasteful “travel time”.easier to use for those with arm/hand motor deficiency.an alternative for disabled users.

Avoids carpal tunnel syndromeassociated with desktop mice.

The Foot Mouse virtuallyeliminates stress on thehand-wrist area by movingmouse control to the feet.

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Head Tracking Mouse

Head Tracking technology has been developed by transmittinga signal receptor on top of the computer monitor (or laptop) andtracking a reflector placed on the user’s head or glasses.

A mouse alternative as this allows the person full control over themovement of the cursor on the screen through movement of thehead.

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Head Tracking Mouse

How does it work?

Once calibrated, the movement of the user’s head relates to whatdirection the onscreen cursor will travel. Calibration is requiredas this matches the users movements with the computers.

Turning head left; directs the mouse to the left.

Turning head right; directs the mouse to the right.

Moving head down; directs the mouse to the bottom of the screen.

Moving head up; directs the mouse to the top of the screen.

Other Devices

Other Human Interface Devices that can be used to interactwith the interface include:

• Speech recognition systems

• Screen magnification devices

The Mackintosh Operating 10.4 System platform has thesesystems built into the computer.

Information can also be found at:http://www.abilityhub.com/index.htm