# Does learning error rates step of DAD2 have to have all samples under study?

**URL:** https://forum.qiime2.org/t/does-learning-error-rates-step-of-dad2-have-to-have-all-samples-under-study/11356
**Category:** User Support
**Created:** [September 2, 2019, 9:28am UTC](https://forum.qiime2.org/t/does-learning-error-rates-step-of-dad2-have-to-have-all-samples-under-study/11356 "2019-09-02T09:28:55Z")
**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 6, 2019, 5:33pm UTC](https://forum.qiime2.org/t/does-learning-error-rates-step-of-dad2-have-to-have-all-samples-under-study/11356/8 "2019-09-06T17:33:42Z")

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Got it!

Ok, I think everything is fine. Dada2 uses the first x samples (sorted) to build up the `n-reads` values and train the error models.

Because errors are similar on each run, this is the default and should work well. You are good to go 🙂

Colin

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