BackgroundWe examine the sensitivity of the Heyneman-Loxley Effect to the influence of an error-prone family background measure in 15 education systems from Southern and Eastern Africa. Our aim is to revisit a claim by Abby Riddell from the November 1989 issue of the Comparative Education Review concerning the reliability of family background measures and the estimation of the Heyneman-Loxley Effect. Three questions guide our study: does national income have an association with the reliability of a family background measure, is the association between a family background measure and student achievement sensitive to measurement error, and is the association between national income and the school effect sensitive to measurement error?MethodsOur analysis relies on the SACMEQ III data archive and, most importantly, a known error-prone family background measure (i.e., socioeconomic status index) and its corresponding measurement error (i.e., conditional standard error of measurement). For each SACMEQ III education system, we calculate the reliability of the socioeconomic status index and examine its association with national income. We use a Bayesian multilevel regression model to estimate naive and correction parameters representing the association between the socioeconomic status index and student achievement. Finally, we explore the associations between national income and the naive and correction estimates for the school effect across SACMEQ III education systems.ResultsWe observe three results. First, the association between national income and the reliability of the socioeconomic status index appears negative among SACMEQ III education systems (albeit questionable due to the small n-size and influential outliers). Second, the association between the socioeconomic status index and student achievement is sensitive to measurement error across content areas and SACMEQ III education systems. Third and finally, the association between national income and the school effect is insensitive to measurement error across content areas and SACMEQ III education systems.ConclusionsThroughout our study, we discuss measurement error, its consequences, and why the correction of error-prone family background measures is important. We highlight the need for auxiliary information for measurement error correction (e.g., reliability ratio, conditional standard error of measurement). Lastly, in addition to encouraging the correction of error-prone family background measures when attempting to replicate the Heyneman-Loxley Effect, we invite further research on improving the reliability and comparability of family background measures.
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