Following up this post, I have large datasets for which I already have a NSBM. I wanted to speed up thinking to an approximate model, so I subsampled a fraction of nodes (randomly chosen) and performed NSBM, then performed a sort of label transfer to the original graph. Except for the fact the partitions at level 0 are now larger than the original ones (as expected) I noticed a general concordance between the communities using subsampled and full graphs. Do you have some literature, ideas or hints about analysis of subsamples?