The Collection Analysis graph is designed to show you the chunk of your library that you’ve selected (between your parameters and Saved Filters) and then show you how that selection of titles (or your entire collection) is performing in your library system or branch.
The performance measurements are based on the Shelf Days, of which you can get details here.
This graph will most often be used to find those titles with which your library is doing the best and the ‘worst.’ The Best titles would be those that you’re circulating at a brisk pace. The Worst performers are simply those titles that are not circulating, and have not done so in quite some time. This measurement can be a great way to gauge the relative health of your collection or even just a portion of it.
Note that Shelf Days are intended to give more weight to titles of which you own multiple copies. So a stack of 20 copies of a title should circulate pretty quickly to justify that larger expenditure.
So, to see those titles that could likely go away without your patrons even noticing, as sad as that may be, click in to that Cool/Stale (bright blue) portion of the graph. From there you can scroll through those titles or, more helpfully, click in to the Title Detail Grid.
From that list, you can create a spreadsheet you can use to create a weeding list.
You can, and should, also use this information to see which titles really do the best in your collection. You likely have a good idea, but it’s nice to have a precise idea. This helps you buy more intelligently for your library and for your patrons. Indeed, having the titles that your patrons want is sort of the point of it all. Having titles they will want…they just don’t know it yet… is sort of the point too, of course. Such an endeavor is both noble and fraught with missteps. Reacting to those missteps to clear them out and fill that shelf space with something new is a great thing.