Using Worldcat services in the library catalog

For the first time we have implemented features into our library catalog that are 'invisible' to most of our library users.

I was inspired to build in these features during my participation in the Worldcat mashathon in Amsterdam on 13-14 May 2009. It was easy to build them in and I hope we do serve unexpected audience this way.

So what are these features ?

If you have ever tried searching worldcat you have probably noticed you can see which libraries hold the title you have just found. At the mashathon I learned that there is an API to give you a list of all the libraries holding copies of a title that is identified by a specific OCLC number. In our library catalog we do not hold the OCLC number, but as I described in a previous post, we can address a OCLC Pica service to get the OCLC number belonging to the dutch PPN which we do hold.

This allowed me to look up all libraries holding copies of a title in our catalog and show them in our full record display. Well, this is not really true. Worldcat will only return the libraries in your 'neigborhood'. This is a pretty large area that is defined by the IP address you are using the service from.

OK, it worked, but I had two problems with it. Firstly. Why would we bother our users with other libraries when we hold the title ourselves ? And secondly. The service always returned libraries in the Wageningen area, since the service was addressed from our server, based in Wageningen. Even though this is a pretty large area, showing not only Dutch libraries, but also German and British libraries and sometimes even libraries on the east coast of Canada and the USA, this is not what you want.

Fortunately, the service allows you to provide an IP address in the request, which will make it ignore our server IP address and will use the IP address provided to decide which libraries to show. So now we pick up the IP address from the browser user. If this a 'Wageningen IP address' we will not invoke the Worldcat API service, so our users will not be bothered by other library holdings. For other IP adresses we will take the IP adress and provide the user with a list of other libraries in their 'neighborhood' holding the title.

If you follow a link like this you may not only notice this new feature, but you may also notice another feature. A feature that will only be shown to you when your IP adress can be related to a library in the Worldcat registry. And only if the person that registered that library also registered a base URL of an OpenURL resolver for that library.

In that case, we will show a link to your local OpenURL resolver to provide you with (mostly full text) services your library will provide for the title you have found in our catalog. Isn't that great !!

One drawback however. Pretty hard to test for us :)

So I am glad Sarah Miller from the library at the National Science Foundation contacted us about a problem they had with this last service. Her SFX button did not lead to a full text link, for a journal they hold. She even pointed out why. We should add 'sfx.ignore_date_threshold=1' to the OpenURL to show full text links from the journal record. She was right. We had this problem when we implemented SFX years ago. A that time the only way to solve this problem was to add year=999 to the OpenURL. We did not do this, but added this to the OpenURL when it was parsed and discovered to be coming from our own journal catalog record. This still works, but only with our own SFX server. We changed this, so you may actually be able to use this new feature.

There is one potential problem with this service. OCLC restricts access to the Worldcat search API to 5000 requests a day. I hope we do not hit that limit very often. It will be so if more than 5000 requests of a full display of a catalog record a day occur. Well this does happen, mostly because of crawlers. I try to filter out a few known crawlers and do not hit the Worldcat service if they request a full record display. And now just hope for the best. ..