In the field of international human rights, the measurement of social phenomena with data and statistics has been integral to chronicling accounts of injustice against humanity. The connection of surveillance data related to social problems may both expose human exploitation and catapult problems into the public arena provoking a political response. In the case of child labour, data collection and analysis has been paramount in harnessing global action against the use of children in exploitative work.

The purpose of this chapter is to provide an overview of child labour data by a discussion of the historical context of data on children's work; available child labour data definitions; methodologies and sources; global estimates on children's work and some discussion on how data collection will be improved in the near future.