Why AI and Excel Don't Mix


Although Python is my usual weapon of choice, I'm not averse to building the occasional model in Excel when the use case fits.

Having originally trained as an actuary, there was a point in my life when I literally lived and breathed Excel. It still feels like second nature - which is probably why I've never felt tempted to use AI assistance when building Excel models, despite using it when writing code.

However, after speaking recently to a fellow data professional about how much AI struggles with Excel, I decided to give it a go.

The first thing I noticed was how fast it was. In less than five minutes, it was done.

The second thing I realised was what a nightmare I had just created for myself. Hundreds of formulae, each hiding in its own cell, each a potential source of error, each requiring me to check it manually.

As astrophysicist Professor Matthew Bailes recently observed in the Australian Financial Review:

"The challenge now is to know that what AI produced is actually correct because you can't use AI to check it."

This is the part of the AI productivity story that tends to get missed.

When I use AI to write code, validation is manageable. Code is designed to be read like text and loops mean hundreds of repetitive calculations can be reduced to a single line. If the logic is right, it's right everywhere.

Excel is an entirely different beast. Every formula lives in its own interconnected cell. There are no loops, no way to verify once and move on. You have to check every individual instance manually. The AI saved me five minutes of production and handed me an hour of tedious validation work.

After five minutes, I lost the will to live. It was like delegating work to a keen but unreliable graduate. The question isn't whether they're fast, it's whether supervising them costs more than doing the work yourself.

Sometimes the answer is no, and AI assistance is clearly the right call. But sometimes, as in the case of Excel, the intelligence required to verify the output exceeds the intelligence required to produce it. In those cases, the productivity gain is an illusion.

Every time you reach for AI assistance, you're making a choice about where to allocate intelligence. It's worth making that choice deliberately.

Talk again soon,

Dr Genevieve Hayes

Data Science Impact Algorithm

Twice weekly, I share proven strategies to help data scientists get noticed, promoted, and valued. No theory — just practical steps to transform your technical expertise into business impact and the freedom to call your own shots.

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