For the definition of usability, I think that learnability is an important part which is mentioned in both Nielson’s article and Blanford & Buchanan’s article. I remember that many libraries have used think-aloud protocol to test the usability of their websites. I think it is a good way to test the learnability in the usability. Like it said in Nielson’s article, learnability means “how easy is it for users to accomplish basic tasks the first time they encounter the design?” It will be very helpful for the librarians to know what the users are thinking when they first use the digital library and search for resources in it. For example, users can tell librarians how they want to get started and what kind of result they expect to get after some clicks.
What effect does a site/system’s usability have on information seeking?
Whether users are satisfied with their information seeking in one digital library depends a lot on the site’s usability. Users will not continue searching in one digital library if it is hard to use. I want to recommend Mestre’s article about the student’s preference for tutorials in the libraries. (Mestre, L. (2012). Student preference for tutorial design: A usability study. Reference Services Review, 40(2), 258-276.) It tests the usability of the tutorials instead of the websites and digital libraries, but some users’ opinions are helpful to other studies,too. The students like the static web page with screen shots more than screencast tutorials. “The difficulties these participants encountered with the screencast tutorials were mainly that they did not feel they could easily go back and find the spot that would help them with a step, even with chapter markers, and that it was difficult to do the steps along with the tutorial.” So, for digital libraries, if it is not very easy to be used, users will just leave and stop their information seeking.
What about librarians? What role do they play in a digital library’s usability and in the overall user experience?
For librarians, they need to design their digital libraries, develop their expertise, teach their users and test the usability. They may search and use their digital libraries as users to test the usability first.