ICT-INFO 1- Topic 4- Selection and use of Input devices and input media

Topic 4 

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  • Created by: Kathryn
  • Created on: 29-10-11 15:38

Topic 4

Selection and use of Input devices and input media

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Selecting a suitable input method

A suitble input method should be:-

  • Automatic
  • Fast
  • Cheap 
  • Accurate
  • Compromise is needed because it is hard to find an input method with all the above
  • Keyboard most common

Manual Method- Mostly human involvement 

Automatic Method- Human batches the work then computer reads it 

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Keyboard

Disadvantages:

  • Slow so not suitable for entering high volumes or fast data entry
  • Costly 
  • Prone to errors
  • Health problems such as RSI

Advantages:

  • Cheap Purchase (included with computer)
  • Most people know how to use a keyboard
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Mouse

  • Make selections
  • Draw lines
  • Size graphical objects
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Voice/speech recognition

  • Enter data via a microphone
  • Ideal for word processing, data bases etc
  • Ideal for lawyers,doctors etc who only use ICT as part of their job 
  • Send emails

Advantages:

  • Faster than typing
  • 99% accurate
  • Cheap

Disadvantages:

  • Takes a while to get used to
  • Not accurate at first
  • Errors due to background noise
  • Does not work with all database software 
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Scanning

  • Capture an image
  • Digitising old non-digital photos, paper documents or book pictures
  • Large organisations
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Producing images from digital cameras

  • Almost replaced older cameras
  • Image editing software
  • USB Lead
  • Memory card
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Webcams

  • Small video cameras
  • Send a moving image of intranet or internet
  • Instant messaging video chats
  • Security eg nurseries
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Digital Video Camera

  • Transmit digital signals
  • Edit
  • Storing
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Other input devices

  • Joystick (games)
  • Touch pad (mouse)
  • Tracker ball (upside down mouse)
  • Digitiser
  • Light pen 
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Magnetic ***** recognition

  • Credit, debit, reward and membership cards
  • Plane and train tickets
  • Date encoded into the magenetic *****
  • Card swiped to read data
  • Data includes the account number, the expiry date and other security info

Advantages:-

  • Few errors
  • Added security
  • Very quick
  • Low chance of fraud 
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Touch Screens

  • Simple
  • Just touch the screen
  • Purchasing train tickets, tourist information etc
  • Almost anyone can use one 
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Bar Code Recognition

  • Light and dark bars off different widths
  • Record goods in supermarkets
  • Warehouse stock control
  • Parcel Tracking
  • Linking books to borrowers in libraries
  • Luggagge lablelling in airports 

Advantages:

  • Fast 
  • Accuate
  • Low printing costs

Disadvantages:

  • Only used for inout of numbers 
  • Laser scanner expensiive, hand held scanners are cheap
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POS Terminals

Point of sale terminals

  • Placed in stored where people pay

Devices that use one:

  • Touch screen displays
  • Keyboards
  • Magnetic ***** readers
  • Bar code readers
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Hand-held input devices

  • Portable
  • Meter readings to read gas and electricity and water
  • The metre takes a reading then inputs it into the the had-held device through wireless communication to send the data to the main computer system
  • Tracking parcels
  • Recoring signatures for reciept of goods
  • Stock taking in shops
  • Taking food orders in restraunts
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Input Media

  • Material in which the data is encoded so that it can be read by an input device and digitised so that it can be input, processed and turned into information
  • Forms with marks on capable of being read by an optical mark reader
  • A bar code
  • A magnetic ***** on a card
  • A picture card used by a digital camera 
  • A CD-ROM used to supply the printer driver for a new printer
  • Bar code 
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Optical Mark Recognition (OMR)

  • Paper-based forms with marks on 
  • Read 3000 sheets on hour
  • Marking multiple choice question answer sheets
  • Reads marks made in bubbles or squares by a optical mark reader

Advantages:

  • Easy to use
  • Cheap
  • Fairly accurate
  • Fast 

Disadvantages

  • Only suiatble for capturing certain data- data needs to be in a form where there are tick style answers
  • Reject rate can be high- if you have not given precise instructions, users may fill in the forms incorrectly which will lead to high rejection rates
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OMR Continued

  • If the form used is creased or folded it may be rejected or cause a jam
  • Voting forms
  • Lottery tickets
  • Market research forms
  • Tests/assessments
  • Product evaluation sheets
  • Time sheets 
  • School/college attendance 
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Optical Character Recognition (OCR)

  • Uses a scanner and special software
  • Looks at the shape of each character
  • Can convert the image of each letter to text which can pass to another software eg a word processor

It can recognise:

  • Typed characters
  • Hand-written characters (neat)

How it works:

1- scans the text 

2-performs the recognition- converts the image to text which can be edited separately. This process looks at the image of each individual letter in turn and then turns it into text which can be put into a software package

3-Save the file for editing (word processor etc)

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Magnetic Ink Character Recognition (MICR)

  • Used to print numbers onto cheques in a magnetic ink
  • Read at very high speed by a magnetic ink character reader
  • Cheque number, bank sort code, account number are pre printed amount is printed after cheque is filled in
  • High cost
  • Limited use 

Advantages:

  • Accurate reading
  • Difficult to forge
  • Can be read easily even when they are folded or crumpled
  • Very fast 

Disadvantages:

  • Expensive
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