Imran Hussain

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Virtual University Human-Computer Interaction
Lecture 43Information Retrieval

• Imran Hussain
• University of Management and Technology (UMT)

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In the Last Lecture

• Various ways in which computer communicate with
  users
• Error messages
• Notifier and conformation dialog boxes

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In the Today Lecture

• Various methods of provided audio feedback
• Negative
• Positive
• Ways in which software application communicates
  and conveys information to the user
• Information retrieval in desktop environment
• Discipline of information architecture within the
  web environment

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Negative audible feedback Announcing user failure

• Negative audible feedback
• noise is emitted when something bad happens

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Positive audible feedback

• Examples
• Closing a door
• Pressing light switch
• Turning key in car ignition

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Available Choices

• No noise vs. noise for negative feedback
• No noise vs. unpleasant noise for negative
  feedback
• No noise vs. soft and pleasant noises for
  positive feedback

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One of the objective with software application is
to communicate brand and identity of the software
application
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Your identity on the desktop

• ways of asserting identity
• Programs icon
• Programs name

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Your programs icon

• Should readily visible
• 2 different sizes icons in windows
• 32 x 32 pixels (desktop)
• 16 x 16 pixels (title bar)
• Icon should be
• High quality
• Visibly distinct at distance from other icons

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Your programs name

• Appears in 2 places
• Title bar (of programs main window)
• Taskbar

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Ancillary application windows

• These are windows that are not really part of the
  applications functionality
• Available on request
• E.g., credit screens

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About boxes

• A simple dialog box that identifies the program
  to user

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About boxes
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Splash screens

• Screens that appear in first instance
• Used for branding and marketing

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Shareware splash screens
1
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Online help

• Online help should be provided but should not be
  substitute for good design

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The index

• Users dont read manuals like book, so index is
  useful
• Indexes should be created carefully and it is
  recommended that it should be done by
  professional indexer
• List of index entries is more important that text
  itself
• provide synonyms
• Example
• User want to black the cell in the table in word
  processor
• how can I set shading of this cell to 100

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Storage and Retrieval Systems

• Storage system
• A method for safekeeping goods in a repository
• A physical system composed of a container and the
  tools necessary to put objects in and take them
  back out again
• Retrieval system
• A method for finding goods in a repository
• A logical system that allows goods to be located
  according to some abstract value (e.g., like
  name, position, etc.)

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Storage and Retrieval in the Physical World

• Storage and retrieval by location
• Indexed retrieval

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Storage and retrieval by location

• In physical world, remembering where we put an
  item its address, or location helps us to
  find it
• Book
• We go to where we left book, or where others
  books are found
• We dont find books by association.

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Indexed retrieval

• For large volumes, storage and retrieval by
  location is not possible
• Libraries Dewey Decimal system
• Give every book an index number based on its
  title and subject matter
• The books are shelved in this numerical order
• If you know number, you can find book

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Indexed retrieval

• How to find number? Use index
• A collection of records that allows you to find
  location of an item by looking up an attribute of
  the item
• 3 copies of cards created for each book
• Each card placed in a separate index
• You physically retrieve book by participating in
  a system of storage (shelves and numbers), but
  logically find the book by participating in a
  system of retrieval (card indices)

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Retrieval methods

• 3 ways to find a document on a computer
• Positional retrieval (remember location)
• Identity retrieval (remember name)
• Associative or attributed-based retrieval

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An attribute-based retrieval system

• Todays desktops cannot adopt an attribute-based
  retrieval system
• Attribute-based system could allow user find
  documents by
• Synonyms
• Related topics
• Attributes

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Information architecture system for web site

• Organizational systems
• Labeling systems
• Navigational systems
• Searching systems