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Check and double-check and triple-check your data

March 27, 2024 Nate Elliott

An Emarketer chart claiming a market will grow eightfold in five years, but showing ninefold growth in four years. Source: Emarketer.

Ready to publish your latest data? Go find someone to check it.

I know, you’ve already checked the data. Maybe even twice. But until you’ve run at least three data checks — including one by someone else — you’re not really ready to publish.

Because even professional data organizations make mistakes. We did when I was at Forrester (fortunately not often). Gartner and McKinsey and everyone else does it too. If data companies get this stuff wrong, you can be certain marketers and journalists do as well.

Witness the fresh example from eMarketer above, claiming spending will increase “nearly eightfold in five years.” This headline contains two glaring errors:

  1. The chart shows ninefold growth, not eightfold. The IDC forecast used here estimates $16 billion of spending in 2023 and $143 billion of spending in 2027. Sixteen goes into 143 approximately 8.7 times, making this nearly ninefold growth.

  2. The forecast covers four years of growth, not five. 2023 is year zero, the starting point. That makes 2024 year 1, 2025 year 2, 2026 year 3, and 2027 year 4. This is a four year range.

The result of these mistakes: IDC’s forecast suggests a compound annual growth rate (CAGR) of nearly 75%, but the eMarketer headline suggests a CAGR of only around 50%. That’s a big difference.

So check and double-check and triple-check your data. One day soon you’ll be glad you did.


Thanks for reading. What’s the worst data checking mistake you’ve seen? Post it in the comments below or on LinkedIn. And if you want good data delivered to your inbox, subscribe here.

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