Members Who Have Taken Advantage of the Training Scholarship Fund

Dr. Jillian Conte used the scholarship fund to aid her attendance to the International Society of Forensic Genetics Workshop in September 2019.

Bayesian Reasoning in Prague at ISFG

By: Dr. Jillian Conte

I was excited to see Dr. John Butler offering a workshop in Scientific Publication during the International Society for Forensic Genetics – who better to learn from than the best? Fast forward two months when I began my registration only to find out the workshop was filled! I registered for my second choice, “Bayesian Reasoning in the framework for Bayesian Networks” with Tomas Furst, a mathematician from Prague, Czech Republic. 

For those of you in casework using likelihood ratios and/or probabilistic genotyping, you know to pay close attention to how you describe your statistics to not fall into the prosecutor’s fallacy. I am not longer in casework, so I needed to make sure I understood this when educating my students. Dr. Furst went through the fallacy with an easy to understand example: you see a person fishing in a lake, what is the probability that the man you see is a fisher, or what is the probability that the fisher you see is a man. These are two different probabilities and one must be careful to calculate properly.

Our workshop continued onward with framing our inferences in Bayesian Network software. Furst used a relatable example, the probability of a baby crying during the night, to help us understand the relationships between events and how they effect the probabilities. The baby awakes and cried during the night because he is wet or because he is hungry. If the baby is wet there is a high probability he is also stinky. If we become more knowledgeable about the situation, let’s say we know the baby is hungry; this changes the probability of the baby crying. We used UnBBayes, a probabilistic network framework, to study this relationship. It was easy to use and quickly calculated probabilities. Furst explained how using probabilities can help large processes in business and manufacturing to identify and resolve issues. These examples really helped understand probabilistic genotyping. 

The workshop was only half a day, we could have easily gone through inferences for two days, but the conference was beginning. Displayed were over 600 posters, and 60 oral presentations. I learned of forensic applications of phenotyping of human pigmentation and greying of hair, ethical and legal issues surrounding forensic genealogy and familial searching, and how non-human DNA is being used increasingly for forensic applications, such as provenancing soil samples.  I shared two pieces of my research involving DNA recovery from immunochromatographic test strips and comparisons of genotyping software. Some vendors were giving out cans of beer instead of pens, as the Czech Republic is known for its beer. This entire experience was jam packed with opportunities to learn and grow as a forensic biologist. The ISFG Congress is held every two years, the next one will be held in Washington D.C. in August 2021. I encourage NEAFS members to attend, it’s a wonderful opportunity to learn about forensic genetics all over the world.