I know of 4 different people who have recently applied and interviewed for 4 different positions at 3 different library systems. Just to make it to the interview process is a ray of hope. I know that the job market in general is "tough" but more so in the library world. The positions are scant and becoming rarer, and the pool of candidates is overflowing. Libraries looking to hire can post a position and be inundated with applications within a few days. Not all of the applicants will be qualified but the libraries are in a position to say, "Jump" leaving applicants asking, "How high?" Libraries are using and abusing this leverage to get applicants to jump through inane hoops in the mindset that by making interviewees go through the whole dog and pony show ("cat and pony" more appropriate for a library setting?), that the best qualified ones will rise to the top.
Now, out of these four individuals that I personally know, not a one of them received word that they didn't get the position. Naturally as time wore on, their hope died a little bit each day. This shouldn't have been the case, maybe those in the hiring decision process never had to personally go through the dread of waiting to hear back themselves. So let me break it down to you, it's like ripping off a band-aid, do it quickly and the pain doesn't last as long compared to the slow deliberate method.
Cut the BS, learn how to ask the right questions, contact references and learn to ask them the right questions, learn how to conduct better interviews and for crying out loud: let people know if they don't get the position.
It's the least you could do instead of dragging these people and their hopes along. How hard is it to send a freaking email nowadays??? If people announce critical life moments in their Facebook statuses, and break-up through texts, you can take the time to send an email. Hell, even a canned, "copypasta" one would do. Here, I'll do it for you:
Hello [Insert Applicant's Name],
We at [Insert Library System Name] would like to thank you for taking the time and effort to apply and interview for the [Enter Position Name] position. I am sending this email to inform you that we have chosen to select a candidate whom we feel is a better match for the position.
Thank you again for your time, good luck in your future endeavors.