# **1. Introduction**

Education quality remains an elusive goal in many developing countries. While countries around the world have made great strides in increasing access to education, much of this education is still of low quality, with low learning outcomes reported in Africa, Latin America, and elsewhere (Bruns & Luque 2014; Filmer & Fox 2014; UNESCO 2014). At the same time, evidence suggests – unsurprisingly – that additional years of schooling have little impact on economic growth in the absence of learning, which is a function of education quality (Hanushek & Woessman 2007). At the same time that governments seek to increase the quality of education, the use of experimental and quasi-experimental methods to measure the effectiveness of education interventions in developing countries has become increasingly common. This has resulted in hundreds of studies from around the world demonstrating the effectiveness (or ineffectiveness) of various interventions at improving student learning. These interventions range from providing information about the quality of schools to parents, to training teachers in scripted literacy instruction, to dropping laptops off for students.

To make sense of all this evidence, various researchers have undertaken systematic reviews of these impact evaluation studies. In 2013 and 2014 alone, at least six reviews of studies seeking to improve student learning in primary schools in developing countries were published in journals or released as working papers. These include Conn 2014, Glewwe et al. 2014, Kremer, Brannen, & Glennerster 2013, Krishnaratne, White, & Carpenter 2013, McEwan 2014, and Murnane & Ganimian 2014.<sup>1</sup> Between them, they review 301 studies from across the developing world: 227 of those studies report learning outcomes, and 152 report enrollment or attendance outcomes. There are differences in the scope of the reviews: Some focus only on primary education whereas others explore both primary and secondary, some only look at learning impacts while others also consider enrollment or attendance, one has a regional focus (Sub-Saharan Africa), two include only randomized controlled trials (RCTs), and three have a well-defined time frame. Yet, as the common denominator, all of these reviews include RCTs implemented in SubSaharan Africa with learning outcomes at the primary school level, published roughly between 1990 and 2010, so the expected overlap is substantial.

Despite that, the main results they highlight for improving learning appear inconsistent. For example, using a subset of the conclusions for each review, Conn (2014) highlights pedagogical interventions as most effective, while McEwan (2014) finds the largest effects for interventions involving computers and technology. Kremer, Brannen, & Glennerster (2013) highlight pedagogical reforms that match teaching to student learning levels as well as the incentives associated with hiring teachers on short-term contracts. Glewwe et al. (2014) emphasize the impact of teacher knowledge, teacher absenteeism and the availability of student desks on student learning. Krishnaratne, White, & Carpenter (2013) underline the importance of learning materials. And Murnane and Ganimian (2014) emphasize providing information about school quality and returns to schooling, among other findings.

> 1 Murnane & Ganimian was published in July 2014 as a National Bureau of Economic Research working paper (Murnane & Ganimian 2014a). For this study, we draw on an updated, unpublished version provided by the authors dated November 18, 2014. Although the sample of studies varies across the two versions, the conclusions are exactly the same.

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