The INFORMS Maryland Chapter
Presents Guest Speaker
Dr. Kevin Ward Drummey
National Security Agency
“A BAYESIAN BELIEF NETWORKS TEASER”
Date: Thursday May 24, 2012
Time: 6PM-7:30PM
Place: 308 Sentinel Dr. Annapolis Junction, MD 20701
Room: Conference Room C1004A
In this presentation, we provide a short tutorial on Bayesian Belief Networks (BBNs) as a teaser for those who may
be interested in this topic for specific applications or research. We introduce a BBN as a graphical probabilistic
model and emphasize the connection of nodes and links in a Directed Acyclic Graph (DAG) with their respective
random variables and statistical dependence relations in a joint probability distribution. We focus on discrete
random variables and show with Conditional Probability Tables (CPTs) how Bayes Theorem and the Law of Total
Probability may be employed to compute conditional probabilities in a natural way and also “in reverse” for a DAG
in a BBN. We discuss both diagnostic and causal reasoning in a BBN as well as the computational complexity of
BBN probability propagation in a DAG, which is facilitated with Pearl’s method. We also mention the importance
of probability elicitation and indicate how numerical probabilities may be qualitatively elicited from subject matter
experts. During our tutorial, we illustrate the concepts of a BBN with NETICA software by employing several small
but effective DAG examples, including an interactive example which allows participants to actually construct and
use a simple BBN.
About the speaker:
Dr. Kevin Ward Drummey is currently Technical Director in the Enterprise Operations Research,
Modeling and Simulation Group (OR/M&S) at the National Security Agency (NSA) within the Department of
Defense. He is also the founder of NSA’s Summer Program for Operations Research Technology (SPORT) and
currently serves as SPORT Technical Director in OR/M&S. In addition, Dr. Drummey is Adjunct Associate
Professor of Statistics at the University of Maryland Baltimore County as well as an Adjunct Faculty Member of
NSA’s Cryptologic School. Dr. Drummey’s expertise is in statistical data analysis and modeling, distribution theory
and simulation, data mining applications, computational algorithm development, and Bayesian statistics. He has
published over 30 technical papers in these areas, mostly within NSA, and has served externally as a referee on
several notable professional journals. Dr. Drummey has presented papers and chaired sessions at both ASA and
INFORMS conferences and has also served on related committees and career panels.
Dr. Drummey has a B.A. Magna Cum Laude in Mathematics from Towson University and an M.A. in Mathematical
Statistics from the University of Maryland College Park. He earned his Ph.D. in Statistics from the University of
Maryland Baltimore County; his dissertation topic was Bayesian robust estimation under the direction of Dr. Bimal
Kumar Sinha. Dr. Drummey is also a certified Lean Six Sigma Green Belt and holds professional certifications in
data mining from SAS Institute and in modeling and simulation from George Mason University. Dr. Drummey is
Past President of the Maryland Chapter of the American Statistical Association and is currently serving as Chapter
Secretary/Treasurer. He is also the proud owner of a Buick Lucerne with the license tag “OUTLIER.”
If you plan on attending, you must
RSVP by May 22, 2012 to Brian Sacash via email: sacash_brian@bah.com