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 [19] 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. © Springer-Verlag Berlin Heidelberg 2006.