  Weight thresholding is a simple technique that aims at reducing the number of
edges in weighted networks that are otherwise too dense for the application of
standard graph theoretical methods. We show that the group structure of real
weighted networks is very robust under weight thresholding, as it is maintained
even when most of the edges are removed. This appears to be related to the
correlation between topology and weight that characterizes real networks. On
the other hand, the behavior of other properties is generally system dependent.
