# Why are missing values not ignored by default?

**URL:** <https://discourse.julialang.org/t/why-are-missing-values-not-ignored-by-default/106756>\
**Category:** Internals & Design\
**Tags:** data, missing-values\
**Created:** [November 26, 2023, 1:45am UTC](https://discourse.julialang.org/t/why-are-missing-values-not-ignored-by-default/106756 "2023-11-26T01:45:36Z")\
**Posts on this page:** 1\
**Showing post:** 64

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**Author:** ![adienes](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/adienes/32/37459_2.png) [@adienes](https://discourse.julialang.org/u/adienes)\
**Post date:** [November 27, 2023, 6:43pm UTC](https://discourse.julialang.org/t/why-are-missing-values-not-ignored-by-default/106756/64 "2023-11-27T18:43:39Z")

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there has to be somewhere to [draw the line](https://jle.aals.org/cgi/viewcontent.cgi?article=1715&context=home) ; not _every_ function can propagate `missing`, but you raise good arguments as to why some of them should

with that being said, I think my ideal world would be:

- binary operators propagate,
- statistical moments and quantiles (and `cor` and `cov`) skip,
- everything else `MethodError`,

so `mean(heights .> 5.5)` would work just fine

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