Computing and the Web

1
Computing and the Web

• Databases Controlling the Information Deluge

2
Overview

• Information Overload
• Overview of Data Collection
• Retrieving Data
• Visualization of Information
• Transforming Data into Information
• Database Structure Design
• Software Applications

3
Information Overload

• Sheer volume of data that is available
• Processed multiple ways to provide information
• Much of the data / information is interrelated
• It is projected that 1 terabyte of data is put
  online on the internet each day
• Assuming that a 500 page book takes 4,750M
• 1 terabyte would hold 220 books
• Thats the equivalent of 6,600 books per month

4
Information Overload

• Relationships based upon the data are more
  complicated due to computers and automation
• Example Grocery store checkout
• Item is scanned by bar code reader
• Bar code is looked up and resolved to item name
• Current price of item is looked up
• Inventory is automatically updated to reflect
  sale
• If inventory drops below established levels, an
  automatic order can be generated to replenish the
  inventory levels of the item

5
Overview of Data Collection

• Previous methods of data collection
• Survey / inventory paper pencil
• Keypunch cards
• Optical mark scan forms
• Current methods of data collection
• Bar codes bar code scanners
• Proximity devices (Easy pass)
• Data probes
• Satellite sensing (imagery, infrared, etc.)
• Intelligent devices generating alerts

6
Retrieving Data

• How data will be retrieved will figure
  prominently in determining how to store it
• Who will use it (single or multiple users)
• How often will it be needed
• How will it be utilized (select information or
  all)
• Example Library system
• All books have a unique identifier
• All patrons have separate identification numbers
• Indexes are built based upon book or patron number

7
Retrieving Data

• Complexity of data is growing with time
• Reducing everything to a number is not natural
  in relation to our brains
• Example FBI fingerprint files
• Database contains over 30 million sets of prints
• Fingerprints can be divided into 1,024 groups
• Before computers 1,400 techs / 24K req per day
• After computers 700 techs / 30K req per day
• Nature of fingerprints makes it difficult to
  reduce them to a number

8
Visualization of Information

• Too much data can be a liability instead of an
  asset
• Need exists to reduce or simplify the data
• Visualization allows large amounts of data to be
  represented in a graphical way
• Superimpose values on charts, maps, or graphs
• Example population growth chart in book

9
Transforming Data into Information

• Data transformation is another means of
  simplifying large amounts of data
• Statistics is the most commonly employed means of
  data transformation
• Percent
• Probability
• Sampling limited selection (beware skewing)
• Normal distribution
• Correlation
• Connection of two related pieces of information
• False correlation looks normal but is erroneous