hierarchical structure of the data
results in (1) a slightly larger effect size estimate
(<math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>μ</mi><mo>=</mo><mn>0.187</mn></mrow><annotation encoding="application/x-tex">\mu = 0.187</annotation></semantics></math>)
and (2) larger standard error of the effect size estimate
(<math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mtext mathvariant="normal">se</mtext><mo>=</mo><mn>0.085</mn></mrow>