New and Noteworthy
We’re happy to announce that our executive director, Patrick Ball, has been presented an honorary degree from Claremont Graduate University in Claremont, California. University President Deborah Freund presented the degree to Patrick at the university’s 88th annual commencement ceremony on Saturday, May 16, 2015. The degree conferred was Doctor of Science honoris causa.
“We at CGU are thrilled that Patrick Ball accepted our Honorary Degree invitation and joined us for commencement,” said Thomas Horan, CGU Professor and Director, Center for Information Systems and Technology. “Patrick’s work stands as a model for conducting first-rate statistic analyses (more…)
This blog is a part of International Justice Monitor’s technology for truth series, which focuses on the use of technology for evidence and features views from key proponents in the field.
As highlighted by other posts in this series, emerging technology is increasing the amount and type of information available, in some contexts, to criminal and other investigations. Much of what is produced by these emerging technologies (Facebook posts, tweets, YouTube videos, text messages) falls in the category we refer to as “found” data. By “found” data we mean data not generated for a specific investigation, but instead, that is generated for some unrelated purpose.
Such data are not new or specific to emerging technology: examples include bureaucratic and administrative records, such as the Historic Archive of the National Police in Guatemala, documents generated by the Documentation and Security Directorate (DDS) in Chad, border crossing records kept by the Albanian border guards during the 1999 conflict between Yugoslavia and NATO, and cemetery registries in Colombia. (more…)
We recently learned about an article by Dr Nafeez Ahmed that criticizes the methods and conclusions of the Iraq Body Count (IBC) and the work of Professor Michael Spagat. Dr Ahmed cites our work extensively in support of his arguments, so we think it’s useful for us to reply.
We welcome Dr Ahmed’s summary of various points of scientific debate about mortality due to violence, specifically in Iraq and Colombia. We think these are very important questions for the analysis of data about violent conflict, and indeed, about data analysis more generally. We appreciate his exploration of the technical nuances of this difficult field.
Unfortunately, parts of Dr Ahmed’s article focus on sources of funding that IBC and Professor Spagat have received, and on speculation about how such funding might affect their substantive conclusions. We find such criticism to distract from the important points of scientific debate. (more…)
Much of the work we do at HRDAG involves estimating the number of undocumented deaths using a statistical technique called multiple systems estimation (MSE, described in more detail here). One of our goals is to make this class of methods more broadly available to human rights researchers. In particular, we are finding that Bayesian approaches are extremely valuable for MSE. Accordingly, we are pleased to offer a new R package called dga (“decomposable graphs approach”) that performs Bayesian model averaging for MSE.
The main function in this package implements a model created by David Madigan and Jeremy York. This model was designed to overcome two of the principal challenges we often face in multiple systems estimation: (1) adequately incorporating statistical uncertainty about the structure of dependence between the lists into the estimates; and, (2) obtaining estimates in the presence of data sparsity that causes maximum likelihood estimation to be highly unstable. In our research, we find these benefits to result from Bayesian approaches to MSE generally. This Bayesian model offers a principled way to account for list dependence uncertainty, allow estimation with sparse data, and, where appropriate, to incorporate expert input about the likely number of undocumented deaths. (more…)