I am running the following script on my microbiome data:
qiime diversity alpha-group-significance
When I view the resulting .qzv file, it tells me that “The following metadata categories have been omitted because the metadata was numerical, not categorical: Year”. I would like to test for differences between sampling years, so how can I tell QIIME to treat this as a factor rather than numeric entry? I see it worked without problem in the Moving Pictures tutorial. Thanks!