Keyboard  Used to input data into application software.  Used for typing in commands to the computer (e.g. Ctrl + P for printing)  The keys are arranged into sections: alphabet keys Function or F keys (e.g. F1, F2, F3) Numeric keys Arrow keys Command keys (e.g. insert, delete, home, end)  Commonly QWERTY layout, recently Ergonomic keyboards are developed to reduce health-related problems such as repetitive strain injury (RSI).

Keyboard  Enable fast entry of new text into a document.  Well-tried technology and a well-known method of entry.  Easy to use for most of people.  Easy to do verification checks as data entered appears on the screen simultaneously. Advantages: Disadvantages:  Some people find it difficult to use.  It is slow when compared to direct data entry e.g. OMR  Needs a valuable desk space to keep.

 A flat board that contains a grid of buttons.  Each button can be programmed to do whatever you want.  An overlay sheet with pictures or symbols is placed on grid so that user can tell what pressing on different areas will do.  These are used when fast input is needed and are ideally suited to selecting from a limited range of choices such as fast food restaurants, such as McDonalds.  Primary schools often use them with young children. The overlay image could be a picture of a farmyard. Pressing on an animal would cause the computer to make the right animal noise. Concept Keyboard

 Enable fast data entry.  It is waterproof.  It is tamper proof, and so are useful in certain applications (e.g. at unmanned airport information kiosks), preventing people from keying in information which could result computer corruption. Advantages: Concept Keyboard

Numeric Keypad  Used in ATM to enter pin, amount etc. Also used in telephones.  Electronic point of sale (EPOS) terminals have it to use in case barcode reader fails to read.  Faster than standard keyboard.  Some are small devices like mobile, so easy to carry.  Difficult to use due to small keys.  Difficult to enter text.  Sometimes order of numbers on it is not intuitive. Advantages: Disadvantages:

Mouse  To open, close and minimise software.  To group, move and delete files.  Useful while editing images e.g. controlling size and position of a drawing on a document. Uses:  Typical mouse with a ball underneath  Optical mouse  Cordless mouse Types:

Mouse Advantages: Disadvantages:  Fast to select an option rather than a keyboard.  Enable rapid navigation through applications and the internet.  Small so take little area.  People with restricted hand/wrist movement can find it hard to operate a mouse.  Can be easily damaged and older type quickly clogs up dirt.  Difficult to use if there is no flat surface e.g. on aeroplane.  Overuse can lead to RSI

Trackerball Advantages: Disadvantages:  It doesn’t need the same fine control as a mouse, so suitable for RSI disability.  People with limited hand/wrist movement find it easier to use than a mouse.  Pointer can be positioned more accurately on the screen than with a mouse.  Takes less desk space than mice since they are stationary.  Not supplied with computer as standard, so more expensive.  User may need training.

Joystick Uses: Disadvantages:  Video/computer games.  Used in simulators e.g. flight simulator, to mimic actual controls.  More difficult to control on-screen pointer with it than a mouse. Advantages:  Easier to navigate round a screen using a joystick rather than a keyboard.  Control is in three dimensions.

Touchpad Advantages: Disadvantages:  Fast to select an option rather than a keyboard.  Enable rapid navigation through applications and the internet.  Since it is integrated into laptop, so no need for a separate mouse.  Can be used even if no flat surface.  People with limited hand/wrist movement can find it hard to operate.  More difficult to control pointer as compared to mouse.  Difficult to do certain operations like ‘drag and drop’.

Touch screen Uses:  For self-service tills, e.g. petrol stations.  For selecting options made on screen, e.g. ATM, airport, railway station, tourist office.  PDA, mobile phones and satellite navigation systems.  Interactive white boards used for education are large touch screens.  Used for computer based training (CBT) where selections are made in answering on screen testing.

Touch screen Advantages: Disadvantages:  Faster and easy to use - intuitive, don't need much training.  No extra peripherals such as a mouse are needed.  Software can alter the screen while it is being used, making it more flexible than a concept keyboard which has a permanent overlay.  Tamper proof.  Limited number of options available.  Can lead to health problems like RSI.  Screen can get very dirty with constant touching.

 A pointing device used by designers and artists to allow natural hand movements to be input to graphics applications.  A stylus is held like a pen and moved over the surface of the tablet. Data about the stylus movements are sent to the computer. Graphics tablet  Used to create ‘hand-drawn’ sketches, drawings and computer graphics.  In countries where characters are complex (e.g. China, Japan), they are used as a form of input.  Used in Computer Aided Design (CAD) work. Uses:

Graphics tablet Advantages: Disadvantages:  Possible to modify drawings before they are input.  An accurate method of drawing, better than mouse or trackerball.  More expensive than other pointing devices, such as mouse.

 A light pen is a device used as a pointing device or to ‘write’ on the screen of a computer.  Contains sensors that send signals to computer whenever light changes are detected.  Only works with Cathode Ray Tube (CRT) monitors. With Thin film Transistor (TFT) monitors, at developmental stage.  Light pens are rarely used today since graphics tablets and high-quality touch screens provide similar functionality. Light pen  For selecting objects on CRT screen.  For drawing on screen (e.g. with CAD packages). Uses:

Advantages: Disadvantages:  More accurate than touch screen  Is small, so can be used where space is an issue.  Easy to use.  At the moment, it works with only CRT monitors.  Not very accurate while drawing. Light pen

 A device that ‘scans’ images, book pages, etc.  The scanned image data is passed to the computer.  The most common type of scanner is the flat-bed scanner which has a glass plate on which the item to be scanned is placed. The item is illuminated and an image of it is captured by a moving scan ‘head’.  Scanned images can be further processed once inside the computer, e.g. OCR of printed text. OCR Scanner