INFORMATION PROCESSING CYCLE I

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INFORMATION PROCESSINGCYCLE I

• What is the information processing cycle? What
  are the varieties of input?

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Definitions.

• Def. 1 Data raw, uninterpreted input.
• E.g. 1568
• Could mean 1,568 units, 1,568,000 units
• (what was the scale?)
• Or 15.68 or 1,568.00 or 1,568,000.00
• Or a password.
• Or an important date in history.

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Definitions.

• Def. 2. Information data which is presented in a
  clear, humanly understandable form.
• Includes formatting e.g. 1,568.00.
• Also includes clear labeling
• Total cost of car repair 1,568.00.
• Can also involve visual presentations e.g.
• graphing (see Unit 2).

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Definitions.

• Def. 3. The information processing cycle the
  set of procedures for processing data into
  information.
• This includes
• 1) INPUT,
• 2) PROCESSING,
• 3) STORAGE AND RETRIEVAL,
• 4) OUTPUT.

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INPUT.

• Anything which has to be brought into RAM can be
  considered as input. This includes
• 1) DATA,
• 2) PROGRAM INSTRUCTIONS,
• 3) COMMANDS,
• 4) USER RESPONSES.

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1. DATA.

• Data can be viewed at many different levels from
  the lowest to the highest.
• 1) CHARACTER, e.g. A
• 2) FIELD, e.g. Anthony
• 3) RECORD, e.g. Anthonys address
• 4) FILE, e.g. all staff addresses
• 5) DATABASE. A linked collection of files

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DATA (cont.).

• The lowest level organization is the character.
• A character can be stored in 1 byte.
• Characters can be either printing or
  non-printing.
• Printing characters include alphanumeric
  characters and special characters.

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DATA (cont.).

• Non-printing characters include control
  characters, which we do not see on the monitor or
  printed output, but which give formatting
  information to the output device.
• E.g. tab, end of paragraph, end-of-file.
• These characters are stored with the printing
  characters in a word processed file.

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DATA (cont.).

• Beyond characters, data can be viewed as grouped
  in increasing levels of abstraction
• (1) A field a single meaningful unit e.g.
• the name or SSN field.
• (2) A record a group of related fields e.g.
  name and SSN for a student.
• (3) A file a group of related records e.g. all
  student records.

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DATA (continued).

• E.g. Bookstore data.
• CHESTERTON, G.K. ORTHODOXY 9.50
• LEWIS, C.S. MERE CHRISTIANITY 5.00
• LEWIS, C.S. THE PROBLEM OF PAIN 5.25
• ZACHARIAS, R. DELIVER US FROM EVIL 15.00
• ZACHARIAS, R. JESUS AMONG MANY GODS 19.95
• This can be analyzed as characters, fields,
  records and a whole file.

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DATA (continued).

• What about databases?
• What are they? Where have you seen them?
• A database is a linked collection of files
  supporting simultaneous searching of the files.
• PCGLOBE has files for each country, linked into a
  database for comparisons between countries.

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2. PROGRAM INSTRUCTIONS.

• These are the binary machine instructions which
  the machine executes. They tell the H/W how to
  process data.
• Analogy 1 a food-processor processes food, but
  it can be instructed in how to process it (fine,
  coarse, etc.)
• Analogy 2 an oven cooks food, but can alter how
  it is cooked.

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3. COMMANDS.

• The user tells S/W what to do.
• 2 kinds of user command.
• External commands outside an application, the
  user selects S/W e.g. from a menu or icon, e.g.
  Word.
• Internal commands inside an application, the
  user selects an option e.g. Format character /
  paragraph.

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4. USER RESPONSES.

• When the application or operating system gives
  messages with options, the user responds.
• E.g.1 dialog boxes within an application.
• Do you want to save before exiting?
• Yes No Cancel

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E.g.2. Windows Security.

• From the desktop or from within an application,
  Ctrl Alt Del.
• Generates several options including
• LogOff, Shutdown, Cancel and Change Password and
  TaskManager.
• Can select Applications Tab to terminate a
  program that is not responding.