Topic: Attribute Tables, Data Types, Joins & Visualization Accuracy

❓ Essential Question

How does attribute data shape a GIS map, and how do data types, joins, and visualization choices affect the accuracy of the story a map tells?

⭐ Key Ideas

• Attribute tables store the data behind every feature.
• Numeric, text, and coded domain fields behave differently.
• Joins connect datasets using a shared key field.
• Wrong data types → wrong symbology → misleading maps.
• Good visualization requires matching data type → renderer correctly.

🔑 Vocabulary

Attribute Table — A spreadsheet of data connected to each feature.

Field — A column (like Name, Population, Type).

Value — A single cell in a field.

Data Type — Defines what kind of values a field stores (string, numeric).

Coded Domain — A list of predefined values for a field.

Join — Linking two tables using a common key.

Relationship — A connection between tables without merging them.