# Creating an Ask data lens: New in Tableau 2021.2

> 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:** 2021-06-26
- **Format:** Video · 1 min read · transcript available
- **Topics:** Data visualisation, Analytics, Data prep
- **Tools:** Tableau (ask data, calculated fields, cloud, dateparse, lod expressions)
- **Canonical:** https://just-tim.com/posts/creating-an-ask-data-lens-new-in-tableau-2021-2
- **Watch:** https://www.youtube.com/watch?v=m0woO20W6bg

I walk through the new Ask Data lens feature in Tableau 2021.2, building a Superstore data source in Desktop with a few calculations before publishing it to Tableau Online. I then create separate shipping and profitability lenses, showing how to narrow fields, add synonyms, and shape recommended visualisations.

## Key takeaways

- Ask Data lenses let you publish one full data source, then create focused 'perspectives' on top of it rather than maintaining separate cut-down data sources for Ask Data.
- A lens can only be created from a published data source on Tableau Server or Online, never from a data source embedded inside a workbook.
- Within a lens you can select which fields are exposed, add synonyms for fields, and hide irrelevant metrics to keep the question experience focused.
- Recommended visualisations become smarter over time as users ask questions and pick chart types, which Tableau captures and surfaces back in the lens.
- You can build multiple lenses from a single data source, each with its own permissions and fields, and they appear as a distinct asset type in Tableau.

## Chapters

- 0:09 What Ask Data lenses solve
- 1:45 Building the data source in Desktop
- 2:36 Creating days-to-ship and order-size calculations
- 7:28 Publishing the data source
- 9:03 Creating a shipping lens
- 12:00 Selecting fields and adding synonyms
- 13:43 Recommended visualisations and chart types
- 17:27 Creating a second profitability lens
- 18:50 Key workflow caveat and next steps

Watch the full video, read the transcript and use chapter deep-links on the page: https://just-tim.com/posts/creating-an-ask-data-lens-new-in-tableau-2021-2

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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