they also make it clear that disadvantaged schools need more support so they can start regarding ethnic differences as a resource for learning rather than an obstacle to learning oecd b identifying the relationship between preprimary education and later performance in school is challenging because attendance at preschool is often correlated with socioeconomic advantage when disadvantaged children enter preschool they already lag behind advantaged children because they are likely to have had fewer play opportunities at home to explore patterns shapes and spatial relations compare magnitudes and count objects