1. What Is Data?
MIS 524

2. Hmmmm. That feels just like “3” or maybe a “4” but definitely not a 5
What is DATA?
Machine “experience”, what a machine makes of its environment
Hmmmm. That feels just like “3” or maybe a “4” but definitely not a 5
THREE POINT FIVE
MIS 524

3. What is INFORMATION?
Human experience of Data: telling us something we didn’t know or weren’t able to predict.
Hey, Schoey, Jones is here for his stock
Was it Jones or Smith we promised the stock to? Gotta find out. Should be Smith, but…
OK, and thanks for the INFORMATION!
MIS 524

4. The Organizational Data “Shadow”
Actual Event
Sources of Error
Real World
Data “Impression”
Error: Lost Data
Error: SpuriousData
Error: IncorrectData
Data “World”
MIS 524

5. Events as Data Each event generates some data
The data are about the objects that play roles in the event
The data describe the objects and perhaps how they relate to one another
The events, too, relate to one another in various ways.
MIS 524

6. Data Events Consider a sales “event”
It involves a number of objects: items sold, salesperson, act of selling, customer, money (objects are also called “entities”)
Each event generates data that describe each of the objects….
MIS 524

7. Describing Objects
Items sold: No. of items, item description or number
Salesperson: Employee number, commission rate
Act of selling: Time, date, counter
Customer: Name and address or membership number
MIS 524

8. How we experience Data
In files, folders, documents, dossiers, descriptions, and envelopes.
Computer-stored information is often referred to as “files”, within which there are “records”, but this terminology isn’t ubiquitous.
MIS 524

9. How to Describe a File Files have these characteristics:
Organization: how individual records relate to each other
Location: where the file can be found
Storage medium: the physical substance the data is encoded on
Access or filing method: how the records can be retrieved
Structure (perhaps related to access)
MIS 524

10. Views of Data Physical View Logical View
As seen by the hardware & software
Logical View
As seen by the users
MIS 524

11. Costs of Data: Data Use Model$ $ $ $ $
Capture
and
Clean
Validate Check Correct Format
File
Relocate Key Record Store
Retrieve
Find Access Format Distribute Display
Maintain
Update Reformat Check, Correct Backup Restore Version
Dispose
Source
Locate Authenti- cate Corrobo- rate
MIS 524

12. Costs of Data: Data Use Model$ $ $ $ $
Capture
and
Clean
File
Retrieve
Maintain
Dispose
Source
Subscriptions
GUIs
Cheaper H/W, Relational Databases
DBMS, non-redundant storage, OODBMS
????
MIS 524