NCGIA Core Curriculum in Geographic Information Science
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Unit 051 - Information Organization andData Structure

Written by: Albert K. Yeung
Ontario Ministry of Northern Development and Mines, Canada

DRAFT - comments invited

This unit is part of the NCGIA Core Curriculum in Geographic Information Science. These materials may be used for study, research, and education, but please credit the author, Albert K. Yeung, and the project, NCGIA Core Curriculum in GIScience. All commercial rights reserved. Copyright 1998 by Albert K. Yeung.

Your comments on these materials are welcome. A link to an evaluation form is provided at the end of this document.

Advanced Organizer

Topics covered in this unit

This unit presents an overview of the terminology and concepts pertaining to information organization and data structure in the context of information science and management. The aim is to provide a general but articulate introduction to the principles and methods of information organization, with special reference to geographic information, that serves as a prerequisite for more advanced studies of data models and database in subsequent units. Topics covered in this unit include:

Learning Outcomes

After learning the material covered in this unit, students should be able to:

Full Table of Contents

Instructors' Notes

Metadata and Revision History

Unit 051 - Information Organization and Data Structure

1. Definitions and Terminology

1.1. Data and information

1.2. Geographic data and geographic information

1.3. The Information Domain

1.4. The data-oriented approach to information systems

2. Information Organization

2.1. The data perspective of information organization

2.1.1. Information organization of descriptive data

2.1.2. Information organization of graphical data

2.2. The relationship perspective of information organization

2.2.1. Categorical relationships

2.2.2. Spatial relationships

2.3. The operating system (OS) perspective of information organization

2.4. The application architecture perspective of information organization

3. Data Structure

3.1. Levels of data abstraction

3.2. Descriptive data structures

3.2.1. Relational data structure

3.2.2. Object-oriented data structure

i = the object's unique identifier (OID)
c = a constructor (which indicates how the object value is constructed)
v = object value

3.3. Graphical data structures

3.3.1. Raster data structure

3.3.2. Vector data structure

3.4. The georelational data structure

4. Data Modeling

4.1. Conceptual data modeling

4.2. Logical data modeling

4.3. Physical data modeling

5. Process Modeling

6. Summary

7. Review and Study Questions

  1. The following three lines of figures have been extracted from a computer file:



    00713344 5000 7.50 1998 12 31 000999999999999
    23112410 0500 7.50 1999 11 01 000999999999999
    33132211 8000 8.00 2001 06 30 000999999999999

    Are these data or information? Explain why.

  3. Explain the importance of information organization and data structure to the functioning of information systems.

  5. Information organization and data structure are key considerations in information system development. Who are the people responsible for identifying, specifying and implementing an organization's requirements for information organization and data structure?

  7. Explain the differences between geographic data and other types of data from the perspective of information organization and data structure.

  9. List the characteristics of the database approach as opposed to the conventional data file approach to data processing.

  11. Explain the difference between a "data model" and a "database model"

  13. Define "categorical relationship" and "spatial relationship". Explain why spatial relationships are more difficult than categorical relationships to implement in data structure.

  15. Information systems are now mostly based on the client/server architecture. Explain the impact of this particular architecture on information organization in system implementation.

  17. What is a relation in the context of data structure? List the characteristics of a relation in terms of data structure.

  19. What is an object in the context of data structure? How is the data structure for an object-oriented database schema constructed?

  21. Explain the relationships among conceptual, logical and physical modeling in database design.

  23. What is a data flow diagram? Explain how a data flow diagram can be used in connection with information organization and data structure.

8. References

Date, C.J. (1995) An Introduction to Database Systems (6th ed.) Addison-Wesley, Reading, MA.

Elmasri, R. and Navathe, S.B. (1994) Fundamentals of Database Systems. Addison-Wesley, Menlo Park, CA.

Everst, G.C. (1986) Data Management: Objectives, System Functions and Administration, McGraw-Hill, New York.

Goodchild, M.F. (1992) Geographic Data Modeling. Computers and Geosciences. Vol. 18, No. 4, pp. 401-408.

Peuquet, D.J. (1991) Methods for Structuring Digital Cartographic Data in a Personal Computer Environment. In Geographic Information Systems: The Microcomputer and Modern Cartography by Taylor, D.R.F. (ed.), Pergamon Press, Oxford.

Pressman, R.S. (1997) Software Engineering: A Practitioner's Approach (4th ed.) McGraw-Hill, New York.


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To reference this material use the appropriate variation of the following format: Albert K. Yeung. (1998) Data Organization and Structure, NCGIA Core Curriculum in GIScience,, posted October 15, 1998.

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Created: October 10, 1998.  Last revised: October 12, 1998.

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