# Features vs. bag of words

**URL:** https://forum.qiime2.org/t/features-vs-bag-of-words/22748
**Category:** General Discussion
**Created:** [April 12, 2022, 3:59am UTC](https://forum.qiime2.org/t/features-vs-bag-of-words/22748 "2022-04-12T03:59:04Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![mcosele](https://forum.qiime2.org/letter_avatar_proxy/v4/letter/m/df788c/32.png) [@mcosele](https://forum.qiime2.org/u/mcosele)
#### Post date: [April 12, 2022, 3:59am UTC](https://forum.qiime2.org/t/features-vs-bag-of-words/22748/1 "2022-04-12T03:59:04Z")

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1. In qiime2's multinomial Naive Bayes classifier, is a "feature" referring to the full-length sequence (e.g. 150 nucleotides) or a k-mer (e.g. 8-mers)?

2. How is a taxonomy classified into seven classes (kingdom, phylum, family, ...). Is the multinomial Naive Bayes classifier applied at each node? I am trying to understand how the hierarchal classification was done.

3. Can I get a dumbed-down explanation of what a "target" is? I am thinking a target is the taxonomy(e.g. k\_\_Bacteria; p\_\_Cyanobacteria; c\_\_Synechococcophycideae; o\_\_Synechococcales; f\_\_Synechococcaceae; g\_\_Synechococcus; s\_\_) but I am not too sure. Maybe answers to the previous two questions will help me out.

Thank you all for all your help so far!