The document discusses impact assessment of digital resources. It defines impact as reaching intended audiences, enabling new research questions, and enabling new approaches to education. It recommends identifying key stakeholders and goals to ensure impact. Metrics for measuring impact include usage analytics, citations, and embedding in other resources. The TIDSR project studied five digital resources and tested impact assessment methods. Interviews found resources transformed access and usage patterns, allowing more comprehensive searches and serendipitous findings. Resources are now part of broader transformations in research workflows, allowing more efficient discovery of sources.