# Geographic roles and default field properties

*Tableau Desktop Foundations Study Guide · Connecting to and Preparing Data · Last updated October 29, 2026 · https://www.certifyforce.com/study-guide/tableau-desktop-foundations/connecting-to-and-preparing-data/geographic-roles-and-default-field-properties*

How to assign the right geographic role (Airport, City, State/Province, ZIP Code/Postcode, Latitude, Longitude) from a field's data type icon and what Tableau generates, and how Default Properties set a field's number format, date format, aggregation, color, sort and comment once for every new view.

- Certification: Salesforce Tableau Desktop Foundations
- Exam section: Connecting to and Preparing Data
- Study guide: https://www.certifyforce.com/study-guide/tableau-desktop-foundations

**Official exam objective:**

> Manage data properties: Rename a data field; Assign an alias to a data value; Assign a geographic role to a data field; Change data type for a data field (number, date, string, Boolean, etc.); Change default properties for a data field (number format, aggregation, color, date format, etc.).

## What the exam expects

- Assign a geographic role from a field's data type icon and pick the role that matches the values (airport codes, city names, postcodes, coordinates).
- Predict what Tableau adds when a role is assigned: Latitude (generated) and Longitude (generated) in the measures area.
- Know that Latitude and Longitude roles need a numeric field, so a text coordinate must change type first.
- Set Default Properties (Number Format, Date Format, Aggregation, Color, Sort, Comment) once in the Data pane so every new view uses them.
- Renaming fields, aliases and changing data types are taught in Field names, aliases and data types.
- Key terms: **geographic role** (tells Tableau which kind of location a field holds so it can geocode it); **geocoding** (assigning latitude and longitude to each value from data built into the Tableau map server); **Default Properties** (field-level settings used whenever the field is added to a view); **default aggregation** (the aggregation a measure gets when first added to a view).

## Key facts

| Fact | Detail | Source |
|---|---|---|
| Assign a role | Data type icon > Geographic Role > role | [Format Geographic Fields in Tableau](https://help.tableau.com/current/pro/desktop/en-us/maps_geographicroles.htm) |
| Geocoding source | Data built into the Tableau map server | [Format Geographic Fields in Tableau](https://help.tableau.com/current/pro/desktop/en-us/maps_geographicroles.htm) |
| Generated fields | Latitude (generated) and Longitude (generated), in the measures area | [Format Geographic Fields in Tableau](https://help.tableau.com/current/pro/desktop/en-us/maps_geographicroles.htm) |
| Airport role | IATA or ICAO codes | [Format Geographic Fields in Tableau](https://help.tableau.com/current/pro/desktop/en-us/maps_geographicroles.htm) |
| City role | Worldwide cities with population of 15,000 or more | [Format Geographic Fields in Tableau](https://help.tableau.com/current/pro/desktop/en-us/maps_geographicroles.htm) |
| Latitude / Longitude roles | Decimal degrees; only for numeric fields | [Format Geographic Fields in Tableau](https://help.tableau.com/current/pro/desktop/en-us/maps_geographicroles.htm) |
| Unrecognized locations | May need custom geocoding | [Format Geographic Fields in Tableau](https://help.tableau.com/current/pro/desktop/en-us/maps_geographicroles.htm) |
| Default Number/Date Format | Set on number and date fields | [Edit Default Settings for Fields](https://help.tableau.com/current/pro/desktop/en-us/datafields_fieldproperties.htm) |
| Default aggregation | Used when the measure is first totaled in the view | [Edit Default Settings for Fields](https://help.tableau.com/current/pro/desktop/en-us/datafields_fieldproperties.htm) |
| Default color | Shared across worksheets using the same data source | [Edit Default Settings for Fields](https://help.tableau.com/current/pro/desktop/en-us/datafields_fieldproperties.htm) |
| Default sort | Also controls the order in filters | [Edit Default Settings for Fields](https://help.tableau.com/current/pro/desktop/en-us/datafields_fieldproperties.htm) |

## Check yourself

- When do you need custom geocoding instead of a built-in role?
- When does a measure's default aggregation take effect?
- Why does a region keep the same color on every worksheet once you set it?
- What does a default sort order affect besides the view?
- Which role fits a column of ISO 3166-1 alpha 3 codes such as FRA?

## Sources

- [Format Geographic Fields in Tableau](https://help.tableau.com/current/pro/desktop/en-us/maps_geographicroles.htm)
- [Edit Default Settings for Fields](https://help.tableau.com/current/pro/desktop/en-us/datafields_fieldproperties.htm)
- [Data Types](https://help.tableau.com/current/pro/desktop/en-us/datafields_typesandroles_datatypes.htm)
- [Save Data Sources](https://help.tableau.com/current/pro/desktop/en-us/export_connection.htm)
- [Create Aliases to Rename Members in the View](https://help.tableau.com/current/pro/desktop/en-us/datafields_fieldproperties_aliases_ex1editing.htm)
- [Plan the Data Source](https://help.tableau.com/current/pro/desktop/en-us/datasource_plan.htm)

## About the full unit

The "Core concepts", "Exam traps" and "Worked scenario" sections of this unit, its 5 linked practice questions, and unlimited timed mock exams are included with the Tableau Desktop Foundations pack (USD $19): https://www.certifyforce.com/practice-exams