# Shannon and Simposon index

**URL:** https://forum.qiime2.org/t/shannon-and-simposon-index/24299
**Category:** General Discussion
**Created:** [September 28, 2022, 10:17am UTC](https://forum.qiime2.org/t/shannon-and-simposon-index/24299 "2022-09-28T10:17:23Z")
**Posts on this page:** 1
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### Author: ![colinbrislawn](https://forum.qiime2.org/user_avatar/forum.qiime2.org/colinbrislawn/32/6221_2.png) [@colinbrislawn](https://forum.qiime2.org/u/colinbrislawn)
#### Post date: [September 28, 2022, 3:03pm UTC](https://forum.qiime2.org/t/shannon-and-simposon-index/24299/2 "2022-09-28T15:03:04Z")

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I've got some examples of how diversity metrics work over here:

> [@Chao1 and Shannon negatively correlated](https://forum.qiime2.org/t/chao1-and-shannon-negatively-correlated/23675):
>
> Hello everybody, I am reporting Chao1 (species richness) and Shannon (eveness) to characterize alpha diversity in different microbiomes. Both indexes are negatively correlated in my data: as Chao1 increases, Shannon decreases. Is that possible? I am having a hard time to find a biological interpretation. Any suggestion? Thanks in advance! Pablo

The short answer is that 'Observed' is a richness _only_ metric, while Shannon and Simpson measure both richness and evenness, so changes in evenness will also be shown.

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