# How to use Explain Data in Tableau Desktop 2019.3 and newer.

> This is content from just-tim, the data-and-analytics channel by Tim Ngwena (formerly 'Tableau Tim'). Tim has 12+ years of hands-on BI experience and covers Tableau most of all, plus Power BI, Looker, Hex, SQL and data modelling, the analytics industry, and the craft of doing the job — always tool-agnostic and honest about the trade-offs.

- **Author:** Tim Ngwena (just-tim, https://just-tim.com/about)
- **Published:** 2019-12-09
- **Format:** Video · 8 min watch · transcript available
- **Topics:** Data visualisation, Analytics, AI & ML
- **Tools:** Tableau (dashboards, explain data, filters)
- **Canonical:** https://just-tim.com/posts/how-to-use-explain-data-in-tableau-desktop-2019-3-and-newer
- **Watch:** https://www.youtu.be/BKodDgjfUDU

I walk through Tableau 2019.3's new Explain Data feature, first showing the manual ad hoc analysis you'd normally do to investigate an outlier in a sales and profit scatterplot, then how Explain Data runs machine learning models to surface that insight automatically. I follow up with a second real-world example using average home ownership duration across London boroughs.

## Key takeaways

- Explain Data runs a range of machine learning models on a selected mark to surface why it behaves as an outlier, such as a higher-than-expected number of records or extreme values.
- You can open any Explain Data finding as a new worksheet, including charts that exclude the extreme value, and the analysis window stays modal so you can keep working alongside it.
- Explain Data only analyses the measures already on your columns, rows and marks; adding a new measure invalidates the analysis and prompts you to rerun it.
- The feature compares your selected mark (shown in blue) against the spread of all other marks (in grey), revealing distributional differences like a higher proportion of terraces and flats or young adults in a given borough.

## Chapters

- 0:00 Manual ad hoc outlier analysis
- 1:58 Running Explain Data on a mark
- 3:55 Adding measures and rerunning
- 5:00 London home ownership example

Watch the full video, read the transcript and use chapter deep-links on the page: https://just-tim.com/posts/how-to-use-explain-data-in-tableau-desktop-2019-3-and-newer

---
just-tim — Data and analytics, with a point of view. · https://www.youtube.com/channel/UC7HYxRWmaNlJux-X7rNLZyw · https://twitter.com/TableauTim · https://www.linkedin.com/in/timngwena