1. Introduction
Educational digital libraries connect content with users. The vast amount of resources and activities within an edu-DL lead to the problem of information overload - how to find useful resources in a reasonable amount of time when there is too much information to manage. The abundance of educational resources in an educational DL (edu-DL) provides opportunities but also creates problems for users when searching for high quality material. Without information on the quality of resources it becomes difficult to locate usable resources from hundreds, if not thousands, of choices. Ideally the user community provides feedback in various forms such as ratings, reviews, comments, etc. that can be helpful to gauge the quality of the resources. However, edu-DLs often host collections with public access that users can navigate through without needing to create an account and provide their feedback on the resources. Lack of user accounts poses a difficulty when building user models since these depend on attributes derived from user accounts.