This document discusses performance measures for libraries and how to illustrate value to stakeholders. It provides guidance on developing an effective performance measurement system, including: aligning measures with organizational strategies and objectives; focusing on outcomes that matter most; using both qualitative and quantitative measures; and communicating results using stories of impact in addition to statistics. Key recommendations include understanding the organizational context, defining success, and interpreting and communicating data in a way that shows how the library contributes to organizational goals.