This issue of The Evaluation Exchange explores the promising practices and challenges associated with taking an enterprise to scale, along with the role that evaluation can and should play in that process. Surprisingly few examples exist of nonprofit efforts that have scaled up and achieved lasting success. A program or approach may be strong and effective in one location, but that does not mean it will work the same way in another. Scaling is a complex process that plays out without a script. But we do know that when we take something to scale, we need to start with a clear sense of what is being scaled, why it is being scaled, how the process will work, and what it should look like in the end. This issue of The Evaluation Exchange helps readers think through some of those questions and options. Articles in this issue include: (1) Broadening the Perspective on Scale (Julia Coffman); (2) Six Steps to Successfully Scale Impact in the Nonprofit Sector (Erin Harris); (3) The Five Meanings of Scale in Philanthropy (Peter Frumkin); (4) Scaling Social Entrepreneurial Impact: The SCALERS Model (Paul N. Bloom and Aaron K. Chatterji); (5) Save the Children's Literacy Programs in Rural America: Evaluation That Informs Scale-Up (Elizabeth Reisner); (6) Lessons from Evaluators' Experiences with Scale (Heidi Rosenberg); (7) A Conversation with Marshall Smith; (8) Developmental Stages for Evaluating Scale (Sarah-Kathryn McDonald); (9) Early Evaluation to Inform Expansion of a Teen Pregnancy Prevention Program (Roblyn Anderson Brigham and Jennifer Nahas); (10) Spreading Our WINGS: Using Performance Data to Prepare for Scale-Up (Ginny Deerin); (11) Applying a Broader Concept of Scale to Evaluate a Funding Strategy (Erin Harris and Priscilla Little); (12) The RALLY Program: Scaling an Inclusive Approach to Intervention and Prevention (Helen Janc Malone); (13) White House Office of Social Innovation and Civic Participation (Harvard Family Research Project); (14) New Releases on Benchmarking Electronic Communications (Katie Chun); and (15) Why Facebook Matters for Nonprofits (Katie Chun). This newsletter also contains an annotated list of papers, organizations, initiatives, and other resources related to the issue's theme. Each article contains lists of key readings and related resources.