I often see statistics on the number of card holders referenced in library materials. For example, in its recent promotional flyer How Libraries Stack Up: 2010, the OCLC compared the number of public library card holders to the number of credit card holders.
I’m curious to know how this statistic is compiled and what it’s meant to convey. Does it reflect library cards issued or library card users? I ask because my hometown library purges records from its cardholder database every 5 years and a librarian I was speaking with from the midwest said her library does so every 3 years. With such long maintenance windows, these databases obviously contain records of people who have died or moved out of their communities.
Also, having a library card and using it are two very different things. I’d be interested to know how these data points correlate.
Readers may also be interested in Thinking ’bout library gate count statistics and Library statistics I’d like to see.
This is another example of how public libraries routinely use measures that “feel good.” In many communities the number of registered card holders exceeds the population of the community. This is due to the fact that people do move and also most libraries serve people who live outside their community. And you noted the long periods of time records are retained before they are purged. A better measure would be the number of registered card holders who live within the jurisdiction. An even better measure would be the number of registered card holders who live within the jurisdiction AND used the library in some way during the past year. The result would be a much smaller number but more reflective of the actual impact of the library in its community.
Hi Joe – thanks for more insights about this metric. I see you’ve published a number of books on library assessment and strategic planning and I appreciate you weighing in.
I forgot about the dimension of users who live outside the community. If I were a library manager, I’d take a close look at who those users are and what they’re doing. I’d see if the data gave me insight into what’s bringing them to my library; could it be that they do not have a library in their community, is it the strength of some of my collections, the appeal of my programs — or perhaps that my library is simply a great place with great staff?
I also wouldn’t rely solely on data to infer what these users value; I’d make a point of getting to know them personally and ask them. Talk about advocates — who better than people who go out of their way to use your library!