Indicators are data or combinations of data used to measure and communicate complex phenomena for policy purposes. They simplify complex issues and provide early warnings. Developing good indicators requires defining policy goals, identifying available data sources, selecting appropriate indicators, and testing them. Biodiversity, socioeconomic, and governance indicators are needed at local and regional scales. Key steps in developing indicators include defining goals, identifying data sources, selecting indicators, and ensuring communication and agreement across countries and scales. Sources of uncertainty can arise from assumptions, models, linking evaluation to action, implementation, and mismatches across temporal and spatial scales.