There are two types of groups, Peers and Constortia, that can be compared to your collection through Gobi.
For each of these two group types there are three categories of comparisons:
1. comparisons of numbers of titles
2. de-duped lists of titles
3. comparisons of activity at the individual title level.
This guide covers Peer Groups. For Consortia data, see YBP Consortia Data in Gobi.
About Choosing Libraries for Comparison
Technically, you can compare My Peer Group (i.e., more than one library) to your library; however, that does not really gain you anything more than doing any search and looking at "Peers" or "GobiTween."
Note, too, that in the Peer Comparison Titles search if you choose "My Peers" it will compare with all members of the peer group you have created. If you want only one of those peer libraries, you will need to eliminate that library from your peer group (EDIT PEER GROUP and SAVE the change).
For example, your peer group includes UCSD and UCB. You want to compare your library with UCB only. If you look under SELECTED LIBRARIES, you will not find UCB listed (or any members of your Peer Group). Thus, if you want UC Berkeley as the comparison library, you'll need to remove it from your Peer Group.
Date Profiled or Pub Date
(1) If your date parameters go back further than two years, the data might not be complete because YBP keeps shipment data for about 24 to 36 months.
(2) On the other hand, if your date parameters are very recent, the data could be distorted. Keep in mind that libraries need time to complete the selection process. There may be many titles that show as not acquired which will, however, be acquired in another month hence.