This dataset provides eight feature classes. The base feature class is called DMAs_dm and isn't generalized. The weighted centroids feature class is called DMAs_dm_cent. The centroids are weighted by the U.S. Block Centroids population distribution. Use the weighted centroids in report aggregation and spatial overlay operations. The DMAs_dm and DMAs_dm_cent feature classes contain all the attributes. There are six generalized boundaries feature classes and called: DMAs_dm_gen2, DMAs_dm_gen3, DMAs_dm_gen4, DMAs_dm_gen5, DMAs_dm_gen6 and DMAs_dm_gen7. Use the generalized boundaries when creating study areas.