This year the Annual General Meeting of the American Society of Questioned Document Examiners (ASQDE) ASQDE 2013 is being held in Indianapolis, Indiana on August 24 through 29, 2013. In keeping with the theme, “Demonstrative Science: Illustrating Findings in Reports and Court Testimony”, I will be presenting a one-day workshop entitled “Conclusion Scales and Logical Inference” on Sunday, August 25.

This will be the 4th iteration of this workshop and I hope it will be one of the more interesting sessions.

The ASQDE is a large and very important group of forensic document examiners. Members come from all parts of North America but mainly the USA, while guest attendees come from all around the world so there is always a great mix of people with different backgrounds and experience. That factor will likely be apparent in the workshop since some of the attendees come from lab systems where a likelihood-ratio approach is being used for evidence evaluation.  And that’s the main topic of the workshop: it is basically an introduction to the coherent logical approach; aka, the likelihood-ratio approach, or simply the LR approach.

This is not the ‘traditional’ approach used in North America, or many other parts of the world, for evidence evaluation or reporting of conclusions.  However, several aspects of our ‘traditional’ approach have been challenged by both external critics and some forensic scientists. Some of the issues can, at least in theory, be addressed very well using the LR approach to evidence evaluation.  Not that it is a panacea for every problem but the LR approach is relatively easy to apply and helps to ensure both the evaluation and reporting of findings are logically coherent and sound.  At the same time, this approach is being advocated for all types of forensic evidence.  Change is coming and it is critical that FDEs learn more about this topic if only to be prepared.

Aside from this particular workshop there is a lot of great stuff planned for the conference.  I hope to post some thoughts about the conference as it proceeds.  That should include, of course, more information about the topics of logical inference, reasoning, evidence evaluation and conclusions.  Stay tuned!!

Followup 1: Okay, just a quick post mid-meeting to say that the workshop/seminar went very well from my perspective.  I was not able to include the ‘advanced’ information at the end since I ran out of time.  A single day just wasn’t enough to cover everything in detail.  At least, not while permitting some necessary and healthy discussion along the way.  I must say I was extremely pleased with the group’s willingness to listen and try to understand.  These concepts are not trivial — they are not easy to get on the first (or even second) listening.  I felt that the reception was generally open and more positive than negative.  And, if I am being honest, that was a bit unexpected.  There were several people who were vocal in their concerns about this approach and generally quite adamant that it cannot work for one reason or another.  I respectfully disagree and point out only that nothing will work if you aren’t willing to give it a try.   For those people I would also say that, as a minimum, it is important to cast a critical eye on what is being done now (the status quo) and really question whether or not it is as ‘perfect’ as they believe.

At any rate, my purpose in giving this workshop was not to ‘sell’ the approach, per se.  That may sound strange to some because at times I am sure that’s how my message came across (some years ago I was told I should have been a preacher — not a great idea for a huge number of reasons best left unsaid but I do understand why they said it).  A sales pitch was most definitely not my intent.  I have a very open mind and, while I may believe one approach is clearly better, I also firmly believe that people need to make up their own minds.  This is a discussion that must take place at the discipline level.  Prove to me that there is something better and I will support it fully.   Indeed, in the sense of this being a discipline discussion, my view of this does not, and should not, matter all that much.  I just hope that after the workshop we will be in a better position to discuss, argue or debate (as necessary) the pros and cons of adopting such an approach, staying with what we use now or choosing something else entirely.  That was the purpose behind the workshop.

It was fun for me (despite working through a terribly sore and hoarse voice). I hope others enjoyed it as well.

Followup 2: A PDF of the presentation has been made available via the ASQDE website. You can get it here (or at

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.