Practical Issues when applying the logical approach to FDE work

Applying the logical approach to evidence evaluation in forensic work can be a challenge. I am the first person to admit that is the case. However, I would argue that (1) a challenge is not something to be avoided — it’s something to take on, and (2) the traditional way of doing things is not easy — it too is a challenge. In fact, it is very important to understand that the logical approach is no more difficult or challenging than what has always been done by forensic document examiners. Indeed, in many ways it is simpler and more straight-forward than our ‘traditional’ approach to such things. This post will touch upon some of the practical issues faced by examiners when applying the logical approach to FDE work.

After studying and using this approach for some time I can assure you that it is not a particularly difficult approach to apply. In select aspects it differs from the traditional approach and, as a result, it feels unfamiliar. Often, this relates to the need to consider things more fully; giving consideration to things we tend to ‘quickly assess’ (or dismiss) when using the traditional approach. But it does not change most things that we do. In fact, it primarily affects the evaluation element of the work; not the elements of analysis or comparison. It requires a different way of thinking about the evaluation process which starts with the focus of the evaluation.

The earliest workshops I presented on this topic were focused, for the most part, on the theory and philosophical bases of the approach, plus the benefits of using it. I did not try to delve into the practical side of things, mainly due to time constraints, but also because I was simply trying to convey its value. FDE’s are, however, a practical lot so I feel that my approach has had limited impact. The most common feedback has been, “I can’t see how it will work in practice…”

That is a fair enough criticism, all things considered. More recently, I have been involved in workshops designed expressly for hands-on practice — after all, there really is nothing like hands-on activities to make something real and tangible. More of those workshops are needed, but they are time-consuming to create. For now, here are some thoughts on these issues deriving mainly from feedback received to date during those workshops.

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ICFIS 2023

The 11th International Conference on Forensic Inference and Statistics, or ICFIS 2023, is set for June 12-15 of this year. It will be held at the Faculty of Law (Juridicum) of Lund University, Lund, Sweden. While I am saddened that I cannot attend this particular meeting, several years ago I had the pleasure of going to the 2014 International Conference on Forensic Inference and Statistics, or ICFIS which was the 9th iteration of the conference. I wrote a blog post about that meeting some time ago.

I can say, based on past experience alone, that this meeting is well worth attending. That’s particularly true if you are interested in the logical approach to evidence evaluation, but it would benefit any forensic scientist. You will not find a better collection of brilliant people all focused on forensic inference, in the broadest sense.

Forensic scientists, lawyers, academics—they will all be there.

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Three principles

Three principles… that’s all.

There are three simple principles1 necessary to ensure proper application of the logical approach to evidence evaluation. Yet, despite this elegant simplicity, some examiners feel the logical approach is too complicated, or confusing, to be used in our work.

Now, to be fair, real-world case things can be a bit complex and challenging from time to time , but that isn’t unique to the logical approach. It is simply a reflection of the nature of forensic document examination. Our work is difficult and challenging at the best of times and every properly trained document examiner must be able to deal with, and explain, complex topics to laypersons. It is the reason why forensic handwriting examination (FHE) expertise is necessary in a court of law.

When one applies the logical approach, that inherent complexity is more exposed… and that is a good thing.

In my opinion, a very strong argument can be made that the logical approach is simpler and easier than any other alternative, even in its most complicated form. That is certainly true once you get over the initial hurdle of comprehension. In my opinion, the real issue for examiners, and for others who argue against the use of the logical approach, is their lack of understanding coupled with a failure to appreciate what the logical approach does to clarify our reasoning processes, how it functions to guide those processes, and how it assists us in explaining and defending our opinions.

Perhaps most important of all, the logical approach demands a different view of the evidence and what it means. Ultimately, it also demands a different view of the role of the examiner. Hence, some people find it difficult to come to terms with the process and what it requires of them.2

I’m often asked for a simple overview or summary of the process — a short-hand description or ‘briefer’ version that explains the basics. Well, here it is…

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Science, experimentation & forensic examination

People sometimes question whether forensic work is scientific in nature. Given that the overall discipline is called ‘forensic science’ this is an interesting, if rather meaningless, question. I say ‘meaningless’ because, practically speaking, it is a non-issue.

Why? Simply because a court may choose to admit anyone as an expert, whether their expertise is scientific, purely experiential, or something else entirely. Nonetheless, it is interesting to consider the issue, if only because forensic document examination is one of those disciplines where this is a common challenge — does it involve any “science” at all?

As a result, this topic is worth some discussion.

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Science vs Pseudoscience

Years ago, in 2013 to be precise, I was invited to speak at the ICA conference held in Montréal, Québec.  The conference had a special session on “distinguishing between science and pseudoscience in forensic acoustics”. Now, I am definitely not an expert in forensic acoustics.  In fact, I know almost nothing about the field other than what I’ve read from time to time. So I wasn’t there to tell the audience anything about forensic acoustics, per se.

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Human Factors in Forensic Handwriting Examination

EWGHFHE cover

One of the projects I had the pleasure to be involved in was the “Expert Working Group for Human Factors in Handwriting Examination”. The WG was convened in 2015 to conduct a scientific assessment of the effects of Human Factors in Forensic Handwriting Examination, with the support of the National Institute of Justice (NIJ) Office of Investigative and Forensic Sciences (OIFS) and the National Institute of Standards and Technology (NIST) Special Programs Office.

It was a lengthy process involving a lot of people drawn from many different domains. The authors of the report included Melissa K. Taylor, Carolyne Bird, Brett Bishop, Ted Burkes, Michael P. Caligiuri, Bryan Found, Wesley P. Grose, Lauren R. Logan, Kenneth E. Melson, Mara L. Merlino, Larry S. Miller, Linton Mohammed, Jonathan Morris, John Paul Osborn, Nikola Osborne, Brent Ostrum, Christopher P. Saunders, Scott A. Shappell, H. David Sheets, Sargur N. Srihari, Reinoud D. Stoel, Thomas W. Vastrick, Heather E. Waltke, and Emily J. Will.

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CSFS Position paper on the Logical Approach

I recently published an editorial in the Journal of the Canadian Society of Forensic Science.  Two versions were published almost simultaneously (the original written in English and a translation in French) entitled, respectively, “CSFS Document Section Position on the Logical Approach to Evidence Evaluation and Corresponding Wording of Conclusions” and “La position de la Section des documents de la SCSJ sur l’approche logique de l’évaluation de la preuve et le libellé des conclusions”.

I wrote these in my capacity as the sitting chairman of the Documents section of the CSFS, on behalf of the members of that section.  The impetus for writing them was to introduce the “logical approach” and related topics to the Canadian forensic community in a ‘formal’ way (hopefully resulting in ongoing discussion) and to provide the public and the courts with the perspective of forensic practitioners who have reviewed the literature and studied this issue in depth. To that end, the document references many initiatives relating to the topic. I will note that it’s not a perfect document but it covers the main points reasonably well.

Please note that this position paper was first written a few years ago.  There was considerable delay in publication relating to the production of an acceptable French-language translation of the document. I must thank Julie Binette who was invaluable in that process. The delay, however, means the references provided in the paper are not fully up-to-date with the very latest developments in this area.

Nonetheless, that shortcoming doesn’t detract from the position expressed.  Today there is even more support and justification than is outlined in the paper. 

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David H. Kaye’s “Forensic Science, Statistics & the Law” Blog

David H. Kaye (DHK) is one of my favourite writers. He is truly prolific and always manages to provide great insights for the reader. His grasp of statistics, logic, and the law is second-to-none, and his ability to communicate those very challenging topics to his audience is equally impressive.

As a mini introduction, David “…is Distinguished Professor, and Weiss Family Scholar in the School of Law, a graduate faculty member of Penn State’s Forensic Science Program, and a Regents’ Professor Emeritus, ASU.” If you would like to see a list of his publications check out http://personal.psu.edu/dhk3/cv/cv_pubs.html 

Yes, DHK has written many things on many topics.1  But I would like to focus on his less formal writings from his blog  Forensic Science, Statistics & the Law.

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CSFS 2018 Conference

The Canadian Society of Forensic Science (CSFS) is holding its 2018 conference and AGM in Gatineau, QC. I’m happy about that because it’s in my own backyard, so to speak.

CSFS conferences vary in their quality and content but this year is looking pretty good.  For example,  the keynote speaker is Dr. Claude Roux whose presentation is entitled ‘Will Forensic Science Reach the End of the Crossroads Soon?’  That’s a tremendous question.  How would you answer it?  Dr. Roux is sure to have an interesting perspective to share with us.  Read more