Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

I've stopped using box plots (2021)

nightingaledvs.com

Post reply on HN
Print view View original

181–190 of 258 posts

Re: I've stopped using box plots (2021)

#181

Post by interroboink »

sanderjd wrote: post #174
j_bum wrote: post #146

Earlier quoted context omitted.

I disagree about violin plots being better. Here is a great rant (borderline lecture) from Angela Collier on why they aren’t [0] [0] https://youtu.be/_0QMKFzW9fw?si=86mRAZRnFCBfSzw0

Could you summarize the criticisms in this (pretty long) video, and what she is proposing as a better alternative (beanplots? or is she criticizing those too?)? I couldn't figure it out from perusing the transcript. I think it's useful to be able to compare the approximate shapes of histograms during exploratory data analysis. Is the thesis of this criticism that this isn't actually a useful thing to do, or that viol…

Her criticisms of violin plots seem to be (1) they combine histogram-style information with box-plot-style information, when you generally would only want one or the other [ie: don't use boxplot for bimodal, don't use histogram when boxplot suffices], (2) The histogram-style information is not comparable between blobs of data, since they're not visually aligned, have no tick marks, etc — a plain histogram is better for this, and (3) she finds them ugly on a personal level.

EDIT: Maybe she'd be fine with using them in an exploratory manner. She seems to mainly be complaining about using them in publications, meant for other people to consume. Also: I did not watch the entire video (:

Re: I've stopped using box plots (2021)

#182

Post by lkdfjlkdfjlg »

weebull wrote: post #164
lkdfjlkdfjlg wrote: post #135

Earlier quoted context omitted.

> What I don't see is anyone saying "box plots are useful because they're the best kind of chart for [specific use case]". Box plots are useful because they're the best kind of chart for when I have multiple populations and I want to quickly glance whether it's reasonable to assume that the populations have the same median, or not (you do that comparing not just the medians of the populations but also the shaded area…

If you're only comparing medians, then just plot the medians. Why a box plot with the quartiles?

Ok, so the difference between medians is 42.7. Is that a lot or a little?

Re: I've stopped using box plots (2021)

#183

Post by davidguetta »

conformist wrote: post #99
quietbritishjim wrote: post #88

Earlier quoted context omitted.

> smooth single-mode distribution That IS a bell curve. While it's true that the Guassian distribution is often called a bell curve or even "the" bell curve, a non-Guassian single mode distribution is still absolutely bell shaped in a general sense. So, although you started your comment with "nah", you're actually in agreement with the content you replied to.

In the mathematical sense this is clearly not true - it’s easy to come up with a smooth single mode distribution that doesn’t look like a bell.

The bell curve IS the smooth single mode with LOWEST ENTROPY.

Re: I've stopped using box plots (2021)

#184

Post by lolc »

fjkdlsjflkds wrote: post #153
lolc wrote: post #76

Earlier quoted context omitted.

Which is why I find the article so compelling because I'd always read box plots as being about variance. To me the plot implied a quite normal distribution.

Note that "not knowing how to correctly interpret a boxplot" is not equivalent to "boxplots are useless".

If people like me are in the audience, they might be worse than useless.

Re: I've stopped using box plots (2021)

#185

Post by kylebenzle »

sigmoid10 wrote: post #12

>box plots always make distributions look bell shaped I feel like this is where the confusion stems from for the author and everyone else here. Box plots don't make anything bell shaped (they don't change the distribution), they assume that your data follows a bell/gaussian shape. This is correct in cases where the central limit theorem can be applied (which is almost everywhere) - but when that is not the case, the…

Yes! You are right and my gears were grinding the whole time reading that article because right of the bat they make some gross and incorrect assumptions.

A box plot isn't trying to show the same thing a histogram is, it's like saying we should stop using Venn diagrams because they confuse people when trying to show the exact amount of overlap, so pie charts are better...

It's silly.

Re: I've stopped using box plots (2021)

#186

Post by timy2shoes »

cycomanic wrote: post #178
canjobear wrote: post #157

Earlier quoted context omitted.

It looks like a spike, not a bell.

A spike is not smooth (typically meaning continuous in the variable and its first derivative), which was one of the conditions.

Then take a Cauchy or a t-distribution. Basically anything with a longer tail than exp(x^2). The Gaussian summary will be misleading because of the tails.

Re: I've stopped using box plots (2021)

#187

Post by iainmerrick »

kaitai wrote: post #171
iainmerrick wrote: post #130

Lots of people defending box plots here -- a lot more than I expected! What I don't see is anyone saying "box plots are useful because they're the best kind of chart for [specific use case]". I can't off-hand think of any situation where I'd rather see a box plot than a strip plot or violin plot. When and why would you want to summarise the data so coarsely and visualize it so un-intuitively?

I deal with a lot of business people who have processes that rely on 15th/85th percentile, or 25th/75th percentile. They want to see the median, the low/high percentiles, the max/min or outliers, and they don't want to see all the data points jittered in between. It's just overwhelming extraneous information. They in fact like tables with those numbers written down, but they want to compare ten different (time series…

That’s a good explanation, thank you!

Re: I've stopped using box plots (2021)

#188

Post by crazygringo »

afiori wrote: post #162
kamma4434 wrote: post #112

Earlier quoted context omitted.

What you say is technically correct, but in the sense where you can put rat poison in One of those ceramic cookie jars they sell in houseware shops. There is nothing wrong in doing it, but it may lead to interesting failure modes Because someone can have implicit assumptions about what’s in there.

Quartiles are relevant for almost any distribution

If by "almost any" you mean "unimodal".

Quartiles are not relevant, i.e. can be highly misleading, for a bimodal distribution or beyond...

Re: I've stopped using box plots (2021)

#189

Post by crazygringo »

WWWWH wrote: post #179
rcxdude wrote: post #41

Earlier quoted context omitted.

Well, to start with, how would you determine that about your distribution in the first place? And if that works well enough, why use a box plot afterwards?

Yes, exactly! Just plot all the bloody data and be done with it. No one is doing this by hand anymore so it is no extra work. To my mind, if you have a genuine EDA attitude you plot it all.

> Just plot all the bloody data and be done with it

Well no, because you can compare the datasets by eye and say questionable qualitative things about them, but you can't make definitively true quantitative statements about them.

Show me two plots of data points and I can show you two people who will in good faith argue over which one has the higher mean or higher median or higher variance. Because you often can't tell.

The entire point of something like a box plot is that it does part of the quantitative analysis for you. You can see where the median is. You can see the width of the quartiles.

Re: I've stopped using box plots (2021)

#190

Post by crazygringo »

Evidlo wrote: post #83
sigmoid10 wrote: post #32

Earlier quoted context omitted.

If you want to see why that is not fully correct you should read the article. For a box plot you need to calculate mean, variance and certain percentiles. These values don't make sense if your distribution does not follow a certain shape (because these values unambiguously define such a shape). See the examples in the article for what happens if you still try to use them in those cases. You can still extract the valu…

> So you can no longer reverse the process I've never understood this to be the purpose of a boxplot, only a means of visualizing a distribution's quartiles. You've gotten a flood of comments from upset people, so I'll keep it short by saying that a boxplot doesn't actually do what you claim for Gaussians, as the 0 and 100 percentile "whiskers" would be at plus/minus infinity. As for a bounded bell-shaped distributio…

> as the 0 and 100 percentile "whiskers" would be at plus/minus infinity

The point is not to plot an ideal Gaussian, the point is to plot the data.

In real life the whiskers are the actual minimum and maximum values observed.

Post reply on HN