As the uptake of voluntary sustainability standards has expanded, stakeholders are increasingly demanding evidence on the performance of certified operations and the outcomes of certification. At the same time, there's growing emphasis on the quality of assurance systems and the need for more robust data to show that standards are effectively addressing high-risk issues such as deforestation, child labour and exploitation. As well as meeting the needs of companies, governments, researchers and the public in general, better monitoring and evaluation (M&E) helps standards themselves to strengthen their systems and add value to their offer.