Data Capture

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• Data Capture

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Data Capture

• Understand the concept of data encoding.
• Describe methods of data capture and identify
  appropriate contexts for their use.

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Collecting Data

• Data is collected, entered into and processed by
  the computer. To make the data acceptable for
  computer reading it needs to be encoded.
• Transforming the data into a computer readable
  form and entering it takes time so methods are
  used to reduce this time as much as possible.
• Consider the difference between finding the
  precise results from reading 20 essays on why
  housewives buy a certain brand of Soap Powder,
  and reading from 20 questionnaires where answer
  boxes are ticked!

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Errors

• The first example of trying to find the relevant
  information from an essay or letter may lead to
  many errors and the results would be unreliable.
• Reading direct from tick boxes should produce
  fewer errors as the data is in a much more user /
  computer friendly form.
• Why is the second example a more computer
  friendly form?
• What possible mistakes could be made by operators
  entering data into a computer?

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• Human involvement when kept to a minimum results
  in fewer errors.
• Keyboard entry used to be the main source of
  input, but other methods are becoming more
  reliable
• Optical Character Recognition (OCR)
• Bar Code reading
• Magnetic Ink Character Recognition (MICR)
• Optical Mark Recognition (OMR)
• Speech Recognition
• Magnetic Strip Readers
• Speech Recognition
• Sensors Touch-screens Mouse etc.

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Optical Character Recognition (OCR)

• This method of input is a form of scanning the
  printed material.
• The printed characters are recognised by the
  computer from the light reflected.
• The part of the form where the light is not
  reflected back forms the image of the character.
• The software used actually reads the image and
  compares it with its own database of images /
  characters, and if recognised converts the image
  to a character that is saved in the computer,
  where it can be manipulated using a Word
  Processor.
• Problems may arise if the original document is
  not the original clarity it may need
  spellchecking or proof-reading.

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Bar Code Reading

• This method of input is a form of scanning the
  bar code.
• The black bars have different widths, and are
  recognised by the computer from the light
  reflected.
• The saved image is read against a decoder and
  made into a number or a character from the
  database of the software.
• Bar coding is used everyday in shops and
  supermarkets where the item of stock is read for
  stocktaking purposes and a price is sent to the
  tills.
• This removes the possible errors of keying in the
  wrong price etc.

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Magnetic Ink Character Recognition (MICR)

• Magnetic Ink characters on forms are printed with
  special magnetic ink.
• When scanned with a Magnetic Ink Character Reader
  the magnetic patterns are read and decoded by the
  software.
• This is a secure system but very complex and
  costly, making it difficult and expensive to
  forge.
• It may be seen on the bottom of bank cheques as a
  series of numbers. When cheques are presented to
  a bank the amount written is also copied in below
  in MICR for added security.
• The benefit of this method is humans can also
  read the numbers and characters they are not in a
  code.

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Optical Mark Recognition (OMR)

• This method of input is a form of scanning a
  document with shaded parts in pre allocated
  spaces.
• The Optical Mark Recognition scans the form and
  records the shaded areas and their positions.
• This is used mainly for data capture, where the
  answer to a question is in the form of a shaded
  box, and are used for the lottery, football pools
  etc.
• Problems may occur if the shaded area contains a
  tick or a line, it may not be recognised,
  problems with folded sheets may also cause a
  misreading.

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Magnetic Strip Readers

• This method of input is a form of reading from
  the magnetic strip of data from the back of a
  card.
• The card is swiped through a reader and is often
  called a swipe card.
• Stores use this type of card as a loyalty card,
  and banks as a credit / debit card.
• Information stored may include loyalty points,
  credit limits, and balances, etc.

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Speech Recognition

• This method of input is much faster than keyboard
  entry, people can speak faster than typing.
• The software has to be trained to the users
  spoken word which takes time to set up, and the
  words need to be spoken clearly with mini breaks
  between words, which slows everything up.
• It does allow processors with lower skills to use
  this system, and makes the flow of documents
  through an organisation more efficient without
  the wait for letters etc to be typed out.

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Sensors

• Sensors are used in capturing data by reading a
  situation every allocated time. The sensor is
  connect to a computer which reads the data sent
  and acts on certain readings.
• A shop security system may use infrared sensors
  to detect movement, readings are sent every 10th
  of a second. If the beam is broken a a different
  reading is sent to the computer causing an alarm
  to ring.
• Other examples are
• a flood warning device,
• temperature warning device,
• pressure device in a busy road monitoring the
  amount of traffic,
• a speed calming camera.

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Other Devices

• Keyboard, and mouse.
• Touch screens.
• Touch type telephones for selecting the right
  service before speaking to an operator.