Alter

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Information and Databases
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Data Modeling Documenting Information
Architecture

• Information Architecture - a conceptualization of
  how the information requirements are met by the
  system.
• From the users viewpoint
• What information is in the system?
• How is the information organized?
• How can users obtain whatever information they
  need?

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Entity Relationship Diagrams

• What kinds of things does the system collect
  information about?
• entities
• What is the relationship between these entities?
• Relationship or association among entities
• What specific information does it collect about
  each of those things?
• attributes

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Entity-relationship diagram for part of a
university registration system
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Types of relationships in entity-relationship
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Possible Attributes for the Entity Types

• DEPARTMENT
• Department identifier
• College
• Department head
• Scheduling coordinator
• COURSE
• Course number
• Department
• Required of department major (y/n)
• Course description
• SECTION
• Section identification number
• Semester
• Year
• Classroom
• Start time
• End time
• Days of week for class meetings

• PROFESSOR
• Employee identification number
• Name
• Address
• Birthdate
• Office telephone
• Social Security number
• STUDENT
• Student identification number
• Name
• Address
• Birthdate
• Telephone
• Gender
• Ethic group
• Social Security number
• OFFICE
• Office number
• Building

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Use of E-R Diagrams

• E-R Diagrams are actually used for the
  non-technical purpose of identifying the types of
  things within the systems scope and the
  relationships among these types of things.

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Types of Data in Todays Information systems

• Pre-defined Data - numerical or text items whose
  meaning are specified explicitly.
• Text - letters, numbers, and other characters
  where the meaning is not pre-defined.
• Images - data in the form of pictures
• Audio - data in the form of sound
• Video - combination of pictures and sound
  displayed over time.
• Future types taste and smell?

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Images produced by information systems
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Review of Some Database Concepts

• What is a database?
• Database management system
• Logical vs. physical views of data
• files, records, fields, keys
• relational databases
• normalization
• SQL
• Push vs. Pull systems.
• Pre-programmed vs. ad-hoc

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Some new Data base Concepts

• Multi-dimensional databases
• most relational database models are optimized to
  support transaction processing.
• Business professionals often wish to analyze
  large amounts of data frequently, e.g. along
  dimensions of product, time period, and store.
• There is a significant difference between
  transaction processing vs. analytical processing.
• Multi-dimensional databases help support data
  warehouses which we will discuss further later in
  the semester.

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Multi-dimensional Databases

• Transaction Systems
• Insert an order for 300 baseballs
• Update this passengers airline reservation.
• close-out accounts payable records for this
  vendor.
• What is the current checking account balance for
  this customer?
• Analytical Support Systems
• Did the sales promotion last quarter do better
  than the same promotion last year?
• Is the five-day moving average for this security
  leading or trailing actual prices?
• Which product line sells best in middle-America
  and how does this correlate to demographic data.

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A Multidimensional database
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Geographic Information Systems

• Organizing data so that it can be accessed by
  pointing at a region on a map.
• Based on spatial or geographic coordinates.
• Marketing and planning applications can visualize
  customers
• The important distinction between GIS and other
  types of information systems is not in the
  database, but in the access method (i.e. through
  maps).

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A geographical information system
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Some Information Concepts

• Data Unorganized facts and figures. (raw
  material)
• Information Data that has been processed into a
  form that is meaningful to the recipient and is
  of real of perceived value in current or
  prospective actions or decisions.
• Information
• adds to a representation
• corrects or confirms previous information
• has surprise value in that it tells us
  something we did not know, or could not predict.
• What is a finished product to one, may be raw
  materials to someone else.

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Definitions Information vs. Knowledge

• Knowledge a combination of instincts, ideas,
  rules, and procedures that guide actions and
  decisions.
• Helping to provide the best available knowledge
  to decision-making is another role of information
  systems

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Relationship Between Data, Information, and
Knowledge

• The difference between data and information is
  easy to remember.
• It is often cited as the reason why systems that
  collect large amounts of information fail to meet
  managements information needs.
• There are many methods of converting data into
  information for decision making.
• Managers take action based on information about a
  current situation plus their accumulated
  knowledge. Actions taken feed the process of
  accumulating more knowledge (experience).
• Example How do medical students become competent
  physicians?

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Relationship Between Data, Information, and
Knowledge
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Attributes of Quality Information

• Timeliness
• Completeness
• Conciseness
• Relevance
• Accuracy
• Precision
• Appropriateness of Form

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Special Characteristics of Information

• Usefulness - depends on combination of
  quality,accessibility,and presentation.
• One persons information may be another persons
  noise.
• Soft data may be as important as hard data.
• Ownership of information may be hard to maintain.
• More information is not always better
  (information overload).
• Politics can often hide or distort information.

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Review Information Needs - Operational vs.
Strategic

• Time frame - historical vs. predictive for the
  future
• Currency - highly current vs. can be quite old
• Expectation - anticipated vs. surprise
• Source - largely internal vs. largely external
• Scope - well-defined, narrow vs. very wide
• Level of aggregation - detail vs. summary
• Frequency - real-time vs. periodic
• Organization - highly structured vs. loosely
  structured
• Precision - highly precise vs. not overly precise

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Question?

• What special attributes or characteristics of
  information have affected you as an individual or
  as part of a group?

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Determinants of Information Usefulness and
Related Roles of Information Systems

• INFORMATION QUALITY
• ACCURACY
• PRECISION
• COMPLETENESS
• AGE
• TIMELINESS
• SOURCE

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Determinants of Information Usefulness and
Related Roles of Information Systems

• INFORMATION ACCESSIBILITY
• AVAILABILITY
• ADMISSIBILITY
• INFORMATION PRESENTATION
• LEVEL OF SUMMARIZATION
• FORMAT
• INFORMATION SECURITY
• ACCESS RESTRICTION
• ENCRYPTION

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Do managers expect the truth?