# AI can't do data analysis? Claude Cowork thinks different. [Un-edited]

> 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:** 2026-01-15
- **Format:** Video · 24 min watch · transcript available
- **Topics:** AI & ML, Analytics, Data visualisation
- **Tools:** Python; Tableau (cloud, filters, table calculations)
- **Canonical:** https://just-tim.com/posts/ai-can-t-do-data-analysis-claude-cowork-thinks-different-un-edited-971eb
- **Watch:** https://www.youtube.com/watch?v=OTxSj9VKRG4

In this unedited, unscripted demo I show how I use Claude Cowork to analyse Tableau's Superstore Excel data without opening any analytics tool, then validate every figure in Tableau itself. Along the way I cover voice-prompting with the Handy speech-to-text tool and why I run the Claude Max plan.

## Key takeaways

- Some of the most efficient AI workflows replace typing with talking — I use the free Mac tool Handy with the Parakeet V3 model for fast, accurate real-time speech-to-text prompting.
- Claude Cowork (only on the $90/month Claude Max plan) can point at a folder, understand TDS, Excel and Hyper files, and even auto-connect the Tableau MCP tools without being asked.
- When AI does numerical analysis in Cowork it writes and runs Python in the background rather than doing 'AI maths', so the computations are accurate and the LLM only narrates the results.
- Validating the output in Tableau confirmed every figure — and Cowork correctly flagged that a 500% sales spike was a single anomalous order (a likely data-entry error), not real growth.
- The right tool matters: the claim that AI can't do data analysis often comes down to how and where you're running it.

## Chapters

- 0:03 Unscripted intro and plan
- 0:45 Voice prompting with Handy
- 2:14 Cowork setup and the Claude Max plan
- 4:23 Asking what's in the folder
- 7:18 Analysing the Excel file
- 10:16 Validating the numbers in Tableau
- 14:40 Anomaly detection and the key insight
- 17:57 Removing the outlier and confirming
- 22:46 Next challenge: a full data model

Watch the full video, read the transcript and use chapter deep-links on the page: https://just-tim.com/posts/ai-can-t-do-data-analysis-claude-cowork-thinks-different-un-edited-971eb

---
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