# Why does taxa data not follow a normal distribution? **URL:** https://forum.qiime2.org/t/why-does-taxa-data-not-follow-a-normal-distribution/9763 **Category:** General Discussion **Tags:** composition, ancom **Created:** [May 14, 2019, 10:58am UTC](https://forum.qiime2.org/t/why-does-taxa-data-not-follow-a-normal-distribution/9763 "2019-05-14T10:58:51Z") **Posts on this page:** 1 **Showing post:** 2
### Author: ![jwdebelius](https://forum.qiime2.org/user_avatar/forum.qiime2.org/jwdebelius/32/9655_2.png) [@jwdebelius](https://forum.qiime2.org/u/jwdebelius) #### Post date: [May 14, 2019, 11:05am UTC](https://forum.qiime2.org/t/why-does-taxa-data-not-follow-a-normal-distribution/9763/2 "2019-05-14T11:05:15Z")
Hi @11114, Welcome! I'm guessing this is your first time working with microbiome data. Have you gone through the tutorials which address feature-based testing? The inherent sparsity of microbiome data has been widely addressed (I suggest [McCurdie et al](https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1003531) and the later response by [Weiss et al](https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-017-0237-y) as follow starting points.) There was a recent post that also gave a bunch of links to _other_ posts about the structure of microbiome data and normalization/rarefaction. > [@Use of rarefacted Table](https://forum.qiime2.org/t/use-of-rarefacted-table/9708): > > Hi, I have a question regarding the use of rarefacted tables. I know that such tables are commonly used only for diversity analysis while are not used as base for other analyzes like differential abundance or network construction. By reading the paper of Swiis and colleagues ([https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5335496/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5335496/)) it seems that the use of rarefacted tables is not a bad choice cause it not lead to an increase of FDR while it should be adopted in cases in which groups with large (~… I'd also check out `q2-decoide`, `q2-composition`, and `q2-gneiss` as starting points for your analysis. Best, Justine P.S. I moved this over to "General Discussion" because its a better fit --- _[View the full topic](https://forum.qiime2.org/t/why-does-taxa-data-not-follow-a-normal-distribution/9763)._