# interpretation of beta-diversity-group-significance box plots
**URL:** https://forum.qiime2.org/t/interpretation-of-beta-diversity-group-significance-box-plots/12550
**Category:** User Support
**Created:** [November 19, 2019, 2:40pm UTC](https://forum.qiime2.org/t/interpretation-of-beta-diversity-group-significance-box-plots/12550 "2019-11-19T14:40:25Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Archana](https://forum.qiime2.org/u/Archana)
#### Post date: [November 19, 2019, 2:40pm UTC](https://forum.qiime2.org/t/interpretation-of-beta-diversity-group-significance-box-plots/12550/1 "2019-11-19T14:40:25Z")
Hello all,
Can anyone pls help me to interpret my beta-diversity-group-significance results?
I have 4 groups each containing 2 samples. total number of sample is 8. I am unable to understand why in all the four plots, the first box has appeared to be a line only. Did I make any mistake?
Any kind of help is highly appreciated.
Best regards,
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### Author:  [@jwdebelius](https://forum.qiime2.org/u/jwdebelius)
#### Post date: [November 19, 2019, 3:37pm UTC](https://forum.qiime2.org/t/interpretation-of-beta-diversity-group-significance-box-plots/12550/2 "2019-11-19T15:37:44Z")
Hi @Archana,
Welcome to the :qiime2: forum!
There aren't any glaring beta-diversity related mistakes, but, let's step back and start talking about beta diversity. So, when we measure beta diversity, we measure a distance. A distance always has to be between two points. (The distance from π» -\> π΅; the distance from π -\> π₯; the distance from πΊπΈ -\> πΈπͺ as a few examples.) For this discussion it doesn't really matter how you measured your distance (although check out the post at the bottom for more about the metrics.)
When you make your beta diversity boxplots, you're plotting the distribution of _distances_, and the n is the number of distances in the boxplot. So, then, if you have π©\_{1} and π©\_{2}, and π\_{1} and π\_{2}, you get the following distances:
- d(π©\_{1}, π©\_{2})
- d(π©\_{1}, π\_{1})
- d(π©\_{1}, π\_{2})
- d(π©\_{2}, π\_{1})
- d(π©\_{2}, π\_{2})
- d(π\_{1}, π\_{2})
If we group the distances, we have one distance that's d(π, π), one distance that d(π©,π©), and four distances that are d(π©, π).... which are exactly the numbers in your boxplot.
The place I might argue you have an issue is therefore not in the math, but in the sample size. A permutative test or kruskal-wallis won't work well with these sample numbers. They're just too small for statistics.
Best,
Justine
* * *
> [@Alpha and Beta Diversity Explanations and Commands](https://forum.qiime2.org/t/alpha-and-beta-diversity-explanations-and-commands/2282):
>
> About the Alpha and Beta Diversity Analysis Tutorial This Alpha and Beta Diversity Community Tutorial (run using QIIME 2017.12) walks you through analyzing the alpha and beta diversity of a sample dataset. Below you will find a link to a small test dataset to download and use in this tutorial. Files used in tutorial The following files, derived from the [Moving Pictures tutorial](https://docs.qiime2.org/2017.12/tutorials/moving-pictures/), are used in this document. [table.qza](https://docs.qiime2.org/2017.12/data/tutorials/moving-pictures/table.qza)[rooted-tree.qza](https://docs.qiime2.org/2017.12/data/tutorials/moving-pictures/rooted-tree.qza)Alpha Diversity Analysis The alpha and alpha-phylogenetic metβ¦
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### Author:  [@Archana](https://forum.qiime2.org/u/Archana)
#### Post date: [November 19, 2019, 5:26pm UTC](https://forum.qiime2.org/t/interpretation-of-beta-diversity-group-significance-box-plots/12550/3 "2019-11-19T17:26:28Z")
Hi Justine,
The way you've explained it is just wow! Thanks a lot. π
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### Author:  [@system](https://forum.qiime2.org/u/system)
#### Post date: [December 20, 2019, 11:26pm UTC](https://forum.qiime2.org/t/interpretation-of-beta-diversity-group-significance-box-plots/12550/4 "2019-12-20T23:26:30Z")
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