Moreover, the domains of early learning are less differentiated than the outcomes that can be observed in older children and adults (National Research Council, 2008(i3j). The undifferentiated nature of skills in early childhood is due, in part, to the fact that early learning occurs across domains with gains in one domain contributing to gains in other domains (Demtriou, Merrell and Tymms, 2017[i53i). This ongoing cycle of reinforcement across domains means that early learning must be assessed using a whole-child approach, recognising the overlapping nature of outcomes for young children.