Administering and reporting results of standardised achievement tests for students has become a common practice in recent years in many developing countries, as these are widely regarded as indicators of success in schooling and/or acquisition of basic skills or knowledge for adult life. However, accurately measuring the cognitive development and achievement of the children in each cohort and getting meaningful scores may prove to be a complex endeavour.

This paper reviews interdisciplinary research on children’s time use. Following the introduction, Section 2 sketches the broad historical and socio-cultural context for time-use studies, recognising that how childhood has been variously understood affects the valuation of children’s activities, roles and relationships and the ways they are experienced. It will become clear that differing views about children’s ‘proper’ time use have coincided with powerful assumptions about children’s roles throughout history, and the ‘value’ of children’s time.

The importance of measures of quality of life and wellbeing, often counterpoised with indicators of economic growth, is especially evident in developing countries. They also have value among marginalised groups in North America and Europe where they highlight how material inequalities impact on experience. Understanding people's experience of their lives as a whole is a challenging and exciting task.

The authors review the contribution of qualitative methods to exploring concepts and experiences of well-being among children and adults living in developing countries. They provide examples illustrating the potential of these methods for gaining a holistic and contextual understanding of people's perceptions and experiences.

"Well-being" is a key concept in the study of children's lives over time, given its potential to link the objective, subjective, and inter-subjective dimensions of their experiences in ways that are holistic, contextualized and longitudinal. For this reason well-being is one of the core concepts used by Young Lives, a 15-year project (2000?2015) that follows the lives of 12,000 children growing up in the context of poverty in Ethiopia, Peru, Andhra Pradesh (India) and Vietnam  (see http://www.younglives.org.uk).