AQA INFO 1 SECTION 4

Selection & Use of Input devices and media

tcowling 2009 from Mott, Leaming & Williams

Input Devices

When devising an IT solution to a problem, you need to consider how the users will input data to the computer.

Key boardMouse

tcowling 2009 from Mott, Leaming & Williams

Scanners

Scanners can be used to input an imagePictures stored in different formats

.bmp & .jpeg etc

Useful for printed hard copiesDepends on clarity of original handwriting or

paper

tcowling 2009 from Mott, Leaming & Williams

Digital Cameras

Connects via a USB port or memory cardImages can be downloaded and stored

Useful for modifying images [red eye]Need accompanying software as well

tcowling 2009 from Mott, Leaming & Williams

Touchpads

Rectangular pad on laptopTouch sensitive by use of the fingerActs as a mouse

Don’t need to carry an additional mouseNot often as easy to use as a mouse

tcowling 2009 from Mott, Leaming & Williams

Optical Character Recognition [OCR]

Device recognises characters by light sensing methods

EG Post Office address reader system or car number plate readers on speed cameras

Easy to store information quicklyClose match is not always the correct match

tcowling 2009 from Mott, Leaming & Williams

Optical Mark Recognition [OMR]

Mark sensing on pre-printed documentsContain boxes which indicate choices marked using carbon

Avoids human keyboard entryForms need to be un-creased to work

properly

tcowling 2009 from Mott, Leaming & Williams

Magnetic Ink Character Recognition[MICR]

Pre-printed with character data in special ink that is magnetised.

Almost used exclusively to read cheques

Minimises fraudNeeds expensive equipment

tcowling 2009 from Mott, Leaming & Williams

Bar Code Readers

Means of identifying items with a unique product code

Read using light and encoded into a readable format

Read quickly with few mistakesExpensive equipment needed

tcowling 2009 from Mott, Leaming & Williams

Speech Recognition

Enable large quantities of data to be input as words verbally

Useful when using hands is not an option [factory/user etc]

User must speak clearly with little variation in dialect

tcowling 2009 from Mott, Leaming & Williams

Which input device to use & when

Volume of data

Speed Nature of System

Ease of use

Technological development

Cost

•Large – automatic equipment is best

•Barcode scanner useful if high speeds necessary

•MICR – needed for specialist input methods such as banking cheques

Conditions may influence choice

Methods constantly updated as new methods introduced

Major factor – could relate to staffing or hardware

tcowling 2009 from Mott, Leaming & Williams

Summary

Automatic input methods remove need to key in dataLarge quantities of data to be read/input quicklyRange of different methods

Keyboard OCR OMR MICR Bar code scanning Speech Recognition

Number of factors considered when choosing an input method Volume of data Cost Speed Ease of Use

tcowling 2009 from Mott, Leaming & Williams