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