This chapter draws together work developing, synthesizing and applying a model for library performance measurement in academic and research libraries. The work comprises publications based on reviews of published studies and primary data from surveys and other investigations. The provenance of the work and the ways in which the individual studies are connected and informed by each other and by the author’s previous work is explained in the chapter. The work follows the author’s long-term quest to understand the idea of value in relation to libraries. At the outset of this investigation there was little work and less clarity about the meaning of and methods for value measurement in libraries. The work argues for a measurement conception for libraries that goes beyond instrumental internal data collection to achieve evaluation of the transcendent worth and contribution of libraries. An intellectual framework for performance measurement is provided in the form of the Value Scorecard, with examples of practical measurement applications to populate the framework. The eight publications are described and their contributions to the field of library performance measurement are analysed in the chapter. The published work and the conference presentations on which they have been based have also made a contribution to the debates in the field, and may have potential application beyond libraries.