Collection Respacing

We are currently undertaking a weeding project – chucking out old multiple copies of textbooks – as part of a broader project to reduce the size of our main collection, and so I’ve been looking into the problem of collection respacing. We have around 900.000 volumes in our main collection stacks, so respacing is going to require a significant effort.

Now, while you may think this is about as interesting as a Senate committee hearing into the price of beets, respacing turns out to be an interesting logistical problem (or nightmare) and a surprisingly difficult problem, due to the number of variables: the height and thickness of individual volumes; the spacing between shelves; … actually not that many, now that I think on it. But still interesting. Trust me.

We can start with a few known metrics: we have standard 26 inch / 900 mm shelf widths, adjustable, with typically seven shelves per bay. There don’t seem to be any “rules” about shelf heights, so we can define a standard of 12 inch centres between shelves, which for seven shelves per bay makes the top shelf 74 inches / 190cm high. And we can add a constraint here: while it is possible to go higher, there are solid health and safety reasons not to, so we can define a maximum height of 74 inches.

There are some “rules of thumb” that can help: based on a standard shelf width of 36 inches, there are tables showing the average number of volumes per shelf. This varies depending on whether you are looking at journals or books, and subject areas – fiction tends to be thinner than, say, engineering, so you can pack more into fiction shelves. The tables assume you want spacing to allow for expansion of the collection over time, so assume 33% free space. In our case, this is too much: we are working on a “steady state” model, where we expect to send to the store, or weed, an equivalent number of books to the number we add each year. [When you have zero chance of getting a new building, or extension, the steady state has to be.] This means we should only require a minimal amount of free space on each shelf, say 10%, to allow for ebb and flow of material. Based on that, we can expect between 25 and 30 volumes per shelf. Average. Depending on the subject area.

The height of books adds another dimension (literally) to the problem. [Thompson] helpfully suggests a shelf spacing of 12 inches will accommodate 90% of a collection – in our case meaning that 90,000 volumes won’t fit with that spacing, which is not very encouraging. In some areas, e.g. 823, the average height is much less, so we could in theory have more shelves per bay (I have seen eight); in other areas, e.g. Art, we have many volumes over that 11 inch height, so we’ll likely have less than seven shelves per bay – perhaps only five. In many cases, journal volumes are taller than 11 inches, so areas with high journal numbers will have fewer shelves per bay.

All these numbers are of course only useful in making broad estimates. If we know how many volumes there are in a given range of call numbers, then we can estimate how many shelves we’ll need for that range. But translating that into bays will require some estimate of average height, or percentage of shelves requiring more than a 12 inch spacing.

So the next step will be to gather some statistics through sampling of heights/spacings.

References at http://del.icio.us/spotrick/collection+management

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Twitter and its use, especially for libraries

Twitter is an interesting beast — social application? — tool? When I first tried it out a few months back, I couldn’t really see the point (for me), partly because I didn’t quite get it: what was I supposed to do with it?

The first obvious use was “waving” — letting everyone else (your “followers”) know what you were up to at any given moment. I think this was the original intention/design goal behind Twitter. Fair enough, but not for me. You need to have friends for that to be useful.

Looking at it, I get the impression that some (many?) users are using Twitter for social bookmarking, letting others know what interesting things they stumbled upon. (Oops!) OK, but, I thought, why would you want to use that when you already have an account with del.icio.us (or Digg; or StumbleUpon; or whatever)? And in truth, Twitter is not really as useful as those other tools for bookmarking.

Twitter really is designed for more ephemeral notifications, so good, I guess for the quick-and-dirty “look at this” kind of message, and its probably better for that than delicious, which is more about permanent bookmarking. Twitter also has some nice mobile phone integration, allowing addition of notes by SMS, and receiving of updates on your phone. Good for those who must keep in touch, and excellent I dare say for today’s “road warriors”.

But six months ago, I wasn’t interested in all that, so … another dead account.

Or so I thought. Recently, I’d been thinking about how we might more easily manage our library web site “news” items, and wanted to be able to feed them directly to the home page from somewhere. The way we manage news now doesn’t lend itself to RSS, and is a pain to update. In one of those ah-ha moments, I realised that Twitter may be perfect for this.

What I have in mind is a Twitter account for the library (with a number of staff having the password). Brief news items (with links to more detailed pages if necessary) would then be posted to Twitter by those staff — not so that users can follow through Twitter, but … ta da! .. so that we can use our RSS feed script to add the feed to our home page. (I wrote a simple AJAX script a while back which will take any RSS feed and write it into a web page as dynamic content.) So … we already have everything we need to make this work, except for that Twitter account — which is there for the asking.

Cool huh?

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