The global commitment to early learning has been expressed in the United Nations (UN) Sustainable Development Goals Agenda (SDG) (United Nations, 2016) and access to support for early learning is considered a human right for all children, whether provided by the family, community, or institutional programs (UNESCO, 2013). Inadequate cognitive stimulation has been identified as one of the key psychosocial risk factors associated with poor child development – a factor that is modifiable, with the right interventions (Walker et al., 2007). Thus, insights into how early learning supports may be delivered effectively in various contexts are essential. To explore the effectiveness of different learning supports requires the measurement of outcomes. Otherwise, supports may be perceived as beneficial by various stakeholders, yet have no demonstrable impact on learning outcomes and may therefore be ineffective investments. This policy note summarises findings regarding the measurement of learning outcomes in Early Childhood Education and Care (ECEC) based on a recent scoping review. The review aims to identify ECEC interventions in economically developing countries between 1998 and 2017 which have been effective in improving children’s learning in the years before school (Jackson et al., 2019).