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I've stopped using box plots (2021)

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

#41

Post by rcxdude »

treflop wrote: post #34
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…

I agree. The author simply used the wrong chart. The author's example has a bimodal distribution (TWO peaks) and chooses a type of chart that has ONE peak (a box plot). A little baffling tbh.

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?

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

#42

Post by rcxdude »

sigmoid10 wrote: post #32
Beldin wrote: post #24

Earlier quoted context omitted.

> Box plots [...] assume that your data follows a bell/gaussian shape. Not sure how to square that with this statement on Wikipedia's page on box plots: Box plots are non-parametric: they display variation in samples of a statistical population without making any assumptions of the underlying statistical distribution[3]

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…

The mean and variance are not features of a box plot. Box plots show the quartiles, which are about the cumulative distribution.

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

#43

Post by quenix »

SillyUsername wrote: post #8

So the diagram should not be used because of an education problem with some audiences? Isn't that a bit like banning cars because some people can't drive? Some diagrams are simply not for mass consumption and this is one, particularly because it is designed to illustrate an interpretation of ranges instead of the direct/linear representation of the raw data. Of course I'd illustrate this fact as a Venn diagram compar…

Driving isn't a medium of communication, so this is an apples to oranges comparison.

If a medium of communication is misunderstood and found to be misleading to your audience, it doesn't really matter whether it's an education problem or not. It ceases to be a good communication medium.

The entire purpose of data viz as the author discussed is to convey ideas to other people. The author argues that people tend to misunderstand this specific chart type. It is valid, then, to dismiss the visualisation as bad for public communication.

Unfortunately, the technical merits of these things don't matter if most people don't understand them.

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

#45

Post by Angostura »

SillyUsername wrote: post #35
mkl wrote: post #25

Earlier quoted context omitted.

When there are alternatives that are clearer and also don't have this education problem, why use box plots? You seem quite keen on them, but why?

There are a few advantages (see visualization section here pls http://en.m.wikipedia.org/wiki/Box_plot ) but my main concern is that the problem is not with the diagram, it's with idea that it's somehow faulty. Sometimes you may want to highlight some core representation of data without the distraction of outliers (yes that does mean some people will use it for deliberate misrepresentation). But in this regard it's u…

The article doesn’t really argue that they are “faulty” just that there are better alternatives in the large majority of cases. I think he makes a compelling argument

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

#46

Post by wesleywt »

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…

This is exactly why the author says you should stop using Box plots. The plot is easy to misinterpret.

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

#47

Post by ohmyiv »

ozyschmozy wrote: post #36
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…

> There are very real use cases for box plots, The author argues otherwise, can you give an example of a use case where box plots would be preferable to the alternatives the author suggests?

> There are very real use cases for box plots,

> The author argues otherwise

No, in the article he says he wouldn't recommend them _in most_ situations. It's a part that a lot of people here seemed to have missed whether arguing for or against box plots.

>Despite making more visual sense than box plots, I still wouldn’t recommend these design concepts or box plots in most situations because…

(Emphasis mine)

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

#48

Post by wesleywt »

bdjsiqoocwk wrote: post #3

The author just has a bad intuition. On the first picture he says "this looks like a small quantity". No, you can't say that. All you can say is that half the data points are in the shades part. You don't know where the rest are.

You need to develop the intuition in the first place to read box-plots. The author argues that there are other plots where you don't require intuition.

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

#49

Post by scrollaway »

montebicyclelo wrote: post #26

The author has experience of teaching box plots in various organisations. The author has found that compared to other types of plots, people struggle to learn how to intepret box plots. The author proposes some alternatives that they believe to be easier for people to interpret: - Strip plots (for few data points) - Jittered strip plots (for more data points) - Distribution heatmap (for even more data points) ---- Th…

Yeah I'm shocked at the awful quality of comments here. This is a clear and straightforward article laying out the issues with box plots and appropriate alternatives, from a professional who works in the field and spends his life explaining these.

And still half the comments are like "But I know better!"... yeah, I'd wager most here don't.

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

#50

Post by SillyUsername »

montebicyclelo wrote: post #26

The author has experience of teaching box plots in various organisations. The author has found that compared to other types of plots, people struggle to learn how to intepret box plots. The author proposes some alternatives that they believe to be easier for people to interpret: - Strip plots (for few data points) - Jittered strip plots (for more data points) - Distribution heatmap (for even more data points) ---- Th…

I'm not suggesting that the other diagrams shouldn't be used, just that box diagrams aren't wrong, they hide data, which is sometimes useful.

I wish we could educate everyone in the ways data can be misrepresented - scale, non 0 axis starting, omitting categories, combining groups, colours, point sizes not representative of data - and they can all be levelled at other graph types, singling out box plots for hiding is no different, but IMHO not justification for not using them with the right audience.

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