ANCOM and W-value

Dear Qiime2 users and developers, I am using ANCOM to perform Differential abundance analysis but I have some doubts regarding the w-value. After reading this excelent topic I ended up understanding what the w-value means but, after testing in some of my samples, I realized that every Differentially abundant ASV is true if the alternative sub-hypothesis (if the ASV is significantly different) to equal or more than 90% of the total ASVs in the sample. Is my observation true?

Hi @Bruno_Andrade,

See the notes about ANCOM’s assumptions here.

ANCOM assumes that the minority of features (< ~25%) are differentially abundant. If you are comparing very different sample types, it will be prone to false positives. See the original paper for more details.

This topic was automatically closed 31 days after the last reply. New replies are no longer allowed.