This how-to guide demonstrates the use of the WorldCat database for comparative analysis.
To find interdisciplinary subjects for comparative analysis: FirstSearch Options.
To restrict your comparisons to the YBP approval universe, rather than WorldCat: YBP Gobi Peer Groups and YBP Consortia Data in Gobi.
(1) See also call numbers identified with and mapped to interdisciplinary subjects (NU and Others).
(2) As with any search of WorldCat, when using FirstSearch:
a. Be sure to examine a sample of the retrieved results to be certain that the results represent what you wish to analyze.
b. Be aware of and informed about what is present and absent in WorldCat (e.g., are all of UIUC's holdings in Russian in the database?).