"The children's librarian knows the children by name, and frequently what type of book they enjoy," she said.
Yes, it was possible that the librarian didn't know who he was chasing.
The librarian can find the name of each book and knows how to locate it but does not care about the information it contains.
Although a considerable amount of generalized research on use has been carried out, many librarians still know relatively little about what their users want.
Unfortunately public librarians know very little at present about users' success (or lack of it) in searching for particular subjects.
Such analyses enable librarians to know the needs of patrons and hopefully provide better services to them.
It is therefore right and sufficient that only the librarian know how to decipher these things.
Furthermore, if the information you seek is not there, the librarian usually knows where to find it.
And that, as librarians know, can be (at least) half the battle.
At my local library the librarians know everyone by name and we know their names.