# Field properties, roles, data types and aliases

*Tableau Data Analyst Study Guide · Connect To and Transform Data · Last updated October 29, 2026 · https://www.certifyforce.com/study-guide/tableau-data-analyst/connect-to-and-transform-data/field-properties-roles-data-types-and-aliases*

Set Default Properties once (sort, color, comment, aggregation, format), fix data types and the mixed-value columns Tableau maps from the first rows of a file, rename and reset fields (in bulk in Tableau Prep), choose between discrete and continuous and between dimension and measure in the view or the Data pane, and alias members, including the published data source limits.

- Certification: Salesforce Tableau Data Analyst
- Exam section: Connect To and Transform Data
- Study guide: https://www.certifyforce.com/study-guide/tableau-data-analyst

**Official exam objective:**

> Customize fields: Change default field properties (types, sorting, etc.); Rename columns; Choose when to convert between discrete and continuous; Choose when to convert between dimension and measure; Create aliases.

## What the exam expects

- Change default properties and data types, and predict what a mixed-value file column becomes.
- Rename and reset fields, and bulk-rename in Tableau Prep.
- Choose when to convert discrete/continuous and dimension/measure, per view or workbook.
- Create aliases, and know what blocks them.
- Basics are in the Desktop Foundations units Field names, aliases and data types, Geographic roles and default field properties, and Dimensions and measures in the Data pane.

Key terms:
- **Default property:** how a field first appears wherever it is used.
- **Mixed-value column:** a file column mixing data types, mapped to one type.
- **Discrete / continuous:** blue fields that create headers versus green fields that create an axis.
- **Dimension / measure:** fields that group the data versus fields that are aggregated.
- **Alias:** an alternate display name for a member of a discrete dimension.

## Key facts

| Fact | Detail | Source |
|---|---|---|
| Default sort | Also controls the order in filter lists | [Edit Default Settings for Fields](https://help.tableau.com/current/pro/desktop/en-us/datafields_fieldproperties.htm) |
| Mixed-value mapping | First 10,000 rows (Excel), first 1,024 rows (CSV) | [Data Types](https://help.tableau.com/current/pro/desktop/en-us/datafields_typesandroles_datatypes.htm) |
| Text in a number column | Treated as Null | [Data Types](https://help.tableau.com/current/pro/desktop/en-us/datafields_typesandroles_datatypes.htm) |
| Data Source page type change | Original fields only, not calculated fields | [Data Types](https://help.tableau.com/current/pro/desktop/en-us/datafields_typesandroles_datatypes.htm) |
| Prep bulk rename | Rename Fields, Clean step only | [Clean and Shape Data](https://help.tableau.com/current/prep/en-us/prep_clean.htm) |
| Can't be continuous | String and Boolean dimensions | [Dimensions and Measures, Blue and Green](https://help.tableau.com/current/pro/desktop/en-us/datafields_typesandroles.htm) |
| Role change scope | Pill: current view; Data pane: all future uses | [Convert a Measure to a Dimension](https://help.tableau.com/current/pro/desktop/en-us/datafields_typesandroles_convertdimtomeas.htm) |
| Aliases | Discrete dimension members only | [Create Aliases to Rename Members in the View](https://help.tableau.com/current/pro/desktop/en-us/datafields_fieldproperties_aliases_ex1editing.htm) |

## Check yourself

- Why does a numeric field named with "ID" or "Key" usually land in the dimensions area?
- Why does a mixed-value column mapped as Text show no Nulls?
- Which field types can have a default number format?

## Sources

- [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)
- [Dimensions and Measures, Blue and Green](https://help.tableau.com/current/pro/desktop/en-us/datafields_typesandroles.htm)
- [Convert a Measure to a Dimension](https://help.tableau.com/current/pro/desktop/en-us/datafields_typesandroles_convertdimtomeas.htm)
- [Convert Fields between Discrete and Continuous](https://help.tableau.com/current/pro/desktop/en-us/datafields_typesandroles_convertdisctocont.htm)
- [Create Aliases to Rename Members in the View](https://help.tableau.com/current/pro/desktop/en-us/datafields_fieldproperties_aliases_ex1editing.htm)
- [Organize and Customize Fields in the Data Pane](https://help.tableau.com/current/pro/desktop/en-us/datafields_dwfeatures.htm)
- [Clean and Shape Data](https://help.tableau.com/current/prep/en-us/prep_clean.htm)

## About the full unit

The "Core concepts", "Exam traps" and "Worked scenario" sections of this unit, its 18 linked practice questions, and unlimited timed mock exams are included with the Tableau Data Analyst pack (USD $19): https://www.certifyforce.com/practice-exams