Papers differing primarily by examined dataset, not analysis technique
In fact, the main contributions in your field are "algorithms", however, data sets are just a bunch of inputs for testing those algorithms and assessing their functionality or efficiency. If the outcomes of your new tests with data set A are exactly the same as dataset B's ones, you might not claim it as a new contribution. But if the results acquired from dataset B lead to some different interpretations about your algorithm's computational capabilities or something, you can consider it as a new contribution.