Timeline for Interpreting box plots with categorical variables
Current License: CC BY-SA 4.0
15 events
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| May 5, 2023 at 10:06 | comment | added | Nick Cox | There are several threads here with linked themes (a) box plots are often enigmatic when based on a small number of distinct values with inevitably many ties (b) there are better ways to plot such data. Here are some examples stats.stackexchange.com/questions/323908/… stats.stackexchange.com/questions/68069/… stats.stackexchange.com/questions/378663/… | |
| May 5, 2023 at 9:40 | history | edited | Nick Cox | CC BY-SA 4.0 |
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| May 5, 2023 at 7:30 | comment | added | Nick Cox | Thanks for adding detail but to my eye the second graph shows more distinct values than that implies. Are you also doing some averaging? or something else extra? | |
| May 5, 2023 at 4:06 | comment | added | kms |
@NickCox The data is y axis is a series with values that are rounded to .5. so values could 2, 2.5, 3, 3.5 and so on. They are not all ints.
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| May 5, 2023 at 0:16 | comment | added | Nick Cox | Thanks for being willing, but the sample is too small for me to try out any alternative plots. To me a crucial detail remains why your plot b appears to show non-integer values beyond the whiskers. | |
| May 4, 2023 at 21:18 | comment | added | kms |
@NickCox I have added some sample data. Basically, I am trying to understand drivers of demand and the relationship between location rating variables which are on a scale of 1-5.
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| May 4, 2023 at 21:17 | history | edited | kms | CC BY-SA 4.0 |
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| May 4, 2023 at 18:30 | comment | added | Nick Cox | Why not show the data, or at least a sample? To my mind behind this question lurks a much more interesting one, how best to plot these data? Too much is hidden here because of ties in the data and the over-emphasis on cut-offs at median $\pm 1.5$ IQR, which are at best arbitrary and at worst quite unhelpful. | |
| May 4, 2023 at 17:42 | comment | added | Nick Cox | To interpret these correctly, we need to know more about the outcomes being plotted. Plot a appears to be of a variable with possible values 0 1 2 3 4 5, and for such variables box plots are of limited use. For two x categories, 50% or more of values are 0; hence 0 is at once minimum, lower quartile and median. Plot b appears to be of a variable with finer resolution. | |
| May 4, 2023 at 17:27 | comment | added | Nuclear Hoagie | Perhaps worth noting that all boxplots have a categorical variable on one axis, this is not any kind of special boxplot. | |
| May 4, 2023 at 17:19 | history | edited | kms | CC BY-SA 4.0 |
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| May 4, 2023 at 17:06 | comment | added | kms |
@StephanKolassa - basically, what can you say about the different categories of demand w.r.t to values on y-axis in both plots?
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| May 4, 2023 at 17:01 | answer | added | Michael Grogan | timeline score: 1 | |
| May 4, 2023 at 16:59 | comment | added | Stephan Kolassa |
Well, these plot the distribution of a particular variable, separately for different groups. For instance, in your upper plot, Values has a larger interquartile spread for extreme than for low values of Demand Volume, as well as a higher median, but the minimum, the maximum and the first quartile are identical between the groups. What exactly is your question?
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| May 4, 2023 at 16:48 | history | asked | kms | CC BY-SA 4.0 |