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Imran Hussain

University of Management and Technology (UMT)

Lecture 43

Information Retrieval

Virtual University

Human-Computer Interaction


In the Last Lecture

Various ways in which computer communicate with users

– Error messages

– Notifier and conformation dialog boxes


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


Negative audible feedback: Announcing user failure

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


Positive audible feedback

• Examples– Closing a door

– Pressing light switch

– Turning key in car ignition


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


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


Your identity on the desktop

• ways of asserting identity– Program’s icon

– Program’s name


Your program’s 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


Your program’s name

• Appears in 2 places– Title bar (of program’s main window)

– Taskbar


Ancillary application windows

• These are windows that are not really part of the application’s functionality– Available on request

– E.g., credit screens


About boxes

• A simple dialog box that identifies the program to user


About boxes

1

2

3

4

5


Splash screens

• Screens that appear in first instance

• Used for branding and marketing


Shareware splash screens

1


Online help

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


The index

• Users don’t 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%”


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.)


Storage and Retrieval in the Physical World

• Storage and retrieval by location

• Indexed retrieval


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 don’t find books by association.


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


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)


Retrieval methods

• 3 ways to find a document on a computer– Positional retrieval (remember location)

– Identity retrieval (remember name)

– Associative or attributed-based retrieval


An attribute-based retrieval system

• Today’s desktops cannot adopt an attribute-based retrieval system

• Attribute-based system could allow user find documents by– Synonyms

– Related topics

– Attributes


Information architecture system for web site

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