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Quartz / bad-data-guide

An exhaustive reference to problems seen in real-world data along with suggestions on how to resolve them.
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Clarify "average per month" in `Data are too coarse` section #15

Closed onyxfish closed 8 years ago

onyxfish commented 8 years ago

Technically the yearly total divided by 12 is the monthly average. Explain why this is a terrible idea.

Explanation from an email I wrote:

With regard to your specific question about "average per month," I think I do need to clarify that section of the guide. Of course the yearly total divided by 12 is technically the monthly average. My point was that if you have no idea of the variation from month to month creating an average can be extremely misleading. Without knowing the distribution of the data it's entirely possible the entire total happened in the first day of the year, which would make expressing it as a monthly average absolutely incorrect.