# R) (Harms, Clifford and Cryer, 2005).

Empirical studies using ECERS-R have generally found positive associations between the quality of early childhood programs and child development. These measures of child development range from language and cognitive skills (Burchinal et al., 2008; Peisner-Feinberg and Burchinal, 1997; Peisner-Feinberg et al., 2001) to social-behavioral development (Burchinal et al., 2008; Sylva et al., 2006). However, the magnitude of the correlations between observed classroom quality and children’s developmental outcomes has been small—ranging from 0.04 standard deviations (Duncan, 2003) to 0.18 standard deviations (Peisner-Feinberg et al., 2001). These small associations, however, are not specific to the ECERS-R alone<sup>7</sup> (Gordon et al., 2013; Vandell and Wolfe, 2000). Other widely-used measures of observed classroom quality – such as the Classroom Assessment Scoring System (CLASS) – have also shown fairly small associations with child development outcomes.<sup>8</sup> In studies that have produced particularly small effect sizes, authors have discussed the idea that effect sizes of observed classroom quality are likely to be underestimated due to measurement error (Duncan, 2003). This suggests the need for further work on addressing the measurement error present in widely-used observational measures of classroom quality like the ECERS-R.

Prior studies on the association between preschool quality and child development also raise concerns of external validity because they have often focused on high-quality, “model” early childhood education programs in the U.S. (Barnett, 1995; Magnuson et al., 2007; Duncan and Magnuson, 2013). Unfortunately, most children in the world do not have access to such highquality programs. As a result, it is important to know whether the positive relationship between preschool quality and child development holds true in other contexts. Studies conducted in the U.S. have looked at the impact of a range of preschool classroom quality on child development (Manguson et al., 2007; Phillips et al., 2001) but it is still rare to find evidence from poor, rural areas in developing countries. Recent studies conducted in Bangladesh (Aboud, 2006), India (Rao, 2010), Kenya, Zanzibar and Uganda (Malmberg et al., 2011) found positive correlations between ECERS-R scores and children’s development outcomes. However, with the exception of an East African study (Malmberg et al., 2011), analyses on the link between observational measures of the quality of the educational environment and child development outcomes have not introduced extensive child, family, and community-level covariates to control for confounding factors. Given the increasing focus on early childhood education interventions in developing countries, there is a need for more rigorous empirical evidence on this topic.

# _Teacher characteristics_

In addition to directly observing the quality of the preschool learning environment, teacher characteristics are another common way of measuring the quality of early childhood programs. There is considerable policy interest in understanding the link between teacher qualifications and children’s developmental outcomes, since governments can more readily regulate a teacher’s level of education, experience, and training than observed classroom quality. In addition, teacher qualifications are often linked to teacher salary, which tends to be the largest expenditure in early childhood education programs in developing countries (Early et al., 2007; Glewwe and Kremer,

> 7 For example, the effect size for the Classroom Assessment Scoring System (CLASS) typically ranges from 0.06 to 0.10 standard deviations (Howes et al., 2008). For an overview of the associations between various measure of classroom quality and child development, see Table 2 in Vandell and Wolfe (2000).

> 8 The Classroom Assessment Scoring System (CLASS) is an observational measure of classroom quality similar in many ways to the ECERS-R.

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