Introduction: The framework for digital library evaluation. Part 1 To whom it may concern: From usage to user: Library metrics and expectations for the evaluation of digital libraries; An agency perspective on digital library evaluation. Part 2 What to place under the evaluation lens: What should we take into consideration when we talk about usability? Users and digital libraries: An insightful story; Towards an infrastructure for digital library performance evaluation; Employing deep log analysis to evaluate the information-seeking behaviour of users of digital libraries. Part 3 Behind the evaluation curtain: The push-me-pull-you of design and evaluation; Extending borders: Outcomes assessment in the era of digital libraries; Digital library service quality: What does it look like? Part 4 How to conduct an evaluation activity: Planning digital library evaluation with logic models; Examining how end users use and perceive digital libraries: A qualitative approach; Investigating users’ perceptions and acceptance of digital libraries: A quantitative approach.