This document discusses the Wellcome Trust's approach to monitoring and evaluating the impact of its funding initiatives. It outlines the Trust's key outcomes of discoveries, applications, engagement, research leaders, research environment, and influence. It then describes the Trust's key indicators to track progress towards these outcomes. The document also discusses challenges to impact evaluation such as ensuring complete self-reporting, tracking career progression over time, attributing outcomes to specific funding, determining individual contributions, and accounting for unpredictable timeframes and unexpected impacts. It proposes that initiatives like ORCID could help address some of these challenges by better connecting researchers, funding, and outputs over time.