Karina G. Diaz Pronouns: she/her/hers Tell us a bit about yourself. My name is Karina Diaz, I’m a research specialist at the Consortium for Policy Research in Education (CPRE) at the University of Pennsylvania. I’m primarily responsible for the design and execution of quantitative analyses for funded research studies, including efficacy evaluations and large-scale projects with experimental and quasi-experimental designs. Prior to this, I collaborated as a research assistant at the STEPP Center at the Institute for Policy Research (IPR) at Northwestern University.

Scientific researchers tend to produce literature on the same topic either to replicate or extend prior studies or due to a lack of awareness of prior evidence (Hedges & Cooper, 2009). Results across studies tend to vary, even when researchers try to replicate studies, due to differences in sample characteristics, research designs, analytic strategies or sampling error (Hedges & Cooper, 2009). Meta-analysis is a set of statistical techniques for synthesizing results from multiple primary studies on a common topic.