you often have to filter through your mini batch or even through your data set to find a good negative sample to go along with this pair of positive samples but I don't I don't really see how their method except that you know it has a bunch of positives and negative samples except for that which I guess you could also apply to the triplet loss there's not really a difference here again your if your method is a contrastive method you do have the problem that if you simply sample at random your negative samples are going to be become easier