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
How did you get into systematic review and/or meta-analysis
While working as a researcher in Chile, I wanted to understand what the
most effective type of professional development educational programs
were. To my surprise, I found a great number of studies, which provided
a variety of different recommendations. I found this to be both exciting
and confusing. I finally came across a meta-analysis that addressed this
research question and that proved to be very useful in clarifying
conclusions previously published on this topic.
Years later, while I was working on my master’s degree at Teachers
College, I took a statistics class with Beth Tipton. She mentioned how
her field of study was meta-analysis and explained many of the
statistical challenges of systemic reviews. I started participating in
her students’ research group, where we reviewed different theoretical
and practical articles on meta-analysis.
What work do you do now that is related to systematic review and/or
My research interests include methods for meta-analysis, design and
analysis of experiments, and advances to missing data approaches. Much
of my methodological work is motivated by statistical inference
questions arising in social research, particularly in educational
I’m currently working on methods to handle missing data of covariates in
meta-regression and on the development of effect size estimators used in
systematic reviews. I’m also collaborating on a meta-analysis that seeks
to evaluate the utility of Emotional approach coping (EAC) in response
to a variety of stressors (i.e., general, health-related,
trauma-related, and interpersonal). These findings may help determine
the most beneficial applications of EAC and serve as a framework for
evaluating the utility of other coping mechanisms.
What do you love about systematic review and/or meta-analysis?
One of the things that I value the most about systematic reviews is that
they provide clarification on conclusions previously published on a
particular topic of interest. It does this by increasing the statistical
power through combined analysis. Meta-analysis results can then help
policymakers and practitioners make evidence-based decisions about
specific interventions, programs, and practices.
Systematic reviews are not only used to aggregate evidence relating to a
specific topic, but also to make clear what is not known and, thus, to
direct new primary research into areas where there might be a gap in the
body of knowledge.
What advice do you have for graduate students and early career
researchers about working in systematic review and meta-analysis
Conducting a meta-analysis is an extensive, meticulous process that may
take months to complete. Before staring a meta-analysis, I would suggest
identifying the question that you want to answer. Understanding if there
is a gap in the literature and whether a systematic review is needed.
Second, make sure your meta-analysis includes both published and
unpublished sources for data collection. Third, explore missingness in
your data and select the appropriate approach to handle missing data. I
would recommend implementing model base methods instead of ad hoc
approaches, such as complete-case analysis and shifting units of
Finally, I would encourage practitioners to provide raw data underlying
their systematic review. Providing access to raw data could contribute
to the advance of science and the improvement of research synthesis