Evaluation of digital libraries assesses their effectiveness, quality and overall impact. To facilitate the comparison of different evaluations and to support the re-use of evaluation data, we are proposing a new logging schema. This schema will allow for logging and sharing of a wide array of data about users, systems and their interactions. We discuss the multi-level logging framework presented in Klas et al 2006 and describe how the community can add to and gain from using the framework. The main focus of this paper is the logging of events within digital libraries on a generalised, conceptual level, as well as the services based on it. These services will allow diverse digital libraries to store their log data in a common repository using a common format. In addition they provide means for analysis and comparison of search history data.
