LECTURE DAY

Geographic Information Science (GISc)

February 9, 2026 | Scientific Foundations of Spatial Analysis

Theory

1. The Science of Where

Geographic Information Science (GIScience) is the scientific discipline that studies the fundamental issues raised by the use of GIS and other spatial technologies.

The GIGO Principle

Garbage In, Garbage Out. In spatial analysis, small errors in positioning can lead to massive errors in overlay analysis or routing. Understanding data quality is paramount.

📖 Read eBook Ch. 3
Data Quality

2. Accuracy vs. Precision

In GISc, we distinguish between how close a measurement is to the truth (Accuracy) and how consistent multiple measurements are (Precision).

🎯 Accuracy

The degree to which information on a map matches real-world values. Systematic errors reduce accuracy.

📏 Precision

The level of detail or repeatability of a measurement. Random errors reduce precision.

Review

Summary of Big Ideas

  • ✓ Uncertainty is Inevitable: We cannot model the complexity of the Earth with 100% fidelity. Metadata is the "birth certificate" of data.
  • ✓ Spatial is Special: Geographic data requires specific statistical methods (Spatial Stats) because it violates the independence assumption of traditional statistics.

🎓 GIScience Quiz

1. If a GPS reading is consistently 10 meters to the East of the actual location, is it:

Precise but not Accurate
Accurate but not Precise
Neither Accurate nor Precise

Lectures

GISc Theory & Applications

Exploring the scientific foundations of spatial data and analysis.

📝 Key Concepts for the Exam

GIScience Fundamentals
  • GIS vs. GIScience: GIS is the tool/software; GIScience is the scientific study of spatial information and spatial reasoning.
  • Accuracy vs. Precision: Accuracy is closeness to truth; Precision is consistency/repeatability.
  • Spatial Data Quality: Includes positional accuracy, thematic accuracy, temporal accuracy, and completeness.
  • Uncertainty: The gap between the real world and our digital representation of it. Often documented in Metadata.
  • Tobler's First Law: "Everything is related to everything else, but near things are more related than distant things." The foundation of spatial autocorrelation.