A research lab wants to find data sets across a large number of different repositories that relate to particular condition. For example, if studying influenza infection, how can it find all data sets that relate to that concept in all the relevant repositories? In short, this scenario calls for finding enough quality datasets to support integrated multi-repository analysis, which in turn builds as complete a picture of a particular disease as possible.
To perform this kind of analysis, the metadata must be both comprehensive and well defined, using unique terms in well-understood fields. This will allow users to identify data sets involving influenza infection, while weeding out infections from other sources in patients who had influenza (or influence vaccines).