Purpose: We examine the impact of advice given by extension agents to Ethiopian farmers, as perceived by the farmers themselves. Design/methodology/approach: Using survey data from 2014, we analyze the perceived impact of advice on farmers' incomes and crop yields. We use a bootstrapped instrumental variable (IV) estimator and the conditional…

In a rigorous evaluation of ASSISTments as an online homework support conducted in the state of Maine, SRI International reported that "the intervention significantly increased student scores on an end-of-the-year standardized mathematics assessment as compared with a control group that continued with existing homework practices."…

Policy-makers are frequently interested in understanding how effective a particular intervention may be for a specific (and often broad) population. In many fields, particularly education and social welfare, the ideal form of these evaluations is a large-scale randomized experiment. Recent research has highlighted that sites in these large-scale…

Graphs are widely used to model structures and relationships of objects in various scientific and commercial fields. Chemical molecules, proteins, malware system-call dependencies and three-dimensional mechanical parts are all modeled as graphs. In this dissertation, we propose to mine and index those graph data to enable fast and scalable search.…