In previous chapters, we learned how geographic information system (GIS) software packages use databases to store extensive attribute information for geospatial features within a map. However, the usefulness of this information is not realized until similarly powerful analytical tools are employed to access, process, and simplify the data. To accomplish this, GIS typically provides comprehensive tools for searching, querying, describing, summarizing, and classifying datasets. With these data exploration tools, even the most expansive datasets can be mined to allow users to make meaningful insights into and statements about that information.

Learning Objectives

• Compare the most frequently used distribution, central tendency, and dispersion measures.
• Explain the basics of the SQL language and understand the various query techniques available in a geographic information system.
• Describe the methodologies available to parse data into various classes for visual representation in a map.

GTCM Alignment

Chapter Sections

• 6.1 Introduction
• 6.2 Descriptions and Summaries
• 6.3 Searches and Queries
• 6.4 Data Classification
• 6.5 References

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