Posted on by RB Ostrum

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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Posted on by RB Ostrum

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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Posted on by RB Ostrum

But doesn’t that mean it is ‘more likely than not’?

When an examiner expresses an opinion along the lines of ‘the findings support one proposition over another proposition’, a question often follows. Specifically, does that opinion mean ‘it is more likely than not that the favoured proposition actually happened’?1 The short answer is “no, it does not mean that.” At least, not necessarily.

In order to reach such a conclusion one must consider information that goes beyond the FDE evidence. As a rule, any opinion I provide will be constrained to the probability of the findings/observations in terms of one of at least two possible explanations.2 Ultimately, equating the two statements is inappropriate because they are not equivalent.3Read more

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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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Posted on by RB Ostrum

Book announcement: Forensic Document Examination in the 21st Century

FDE in the 21st CenturyI am very pleased to have been contributor to a new textbook, Forensic Document Examination in the 21st Century.  The text was edited by Jan Seaman Kelly and Miriam Angel and will be published by CRC Press.

My personal contribution is chapter 3 entitled “The Logical Approach to Evidence Evaluation”.   The complete list of contributors is impressive and includes Jan Seaman Kelly, Miriam Angel, Brett M.D. Bishop, Rigo Vargas, Mara L. Merlino, Samiah Ibrahim, Lucinda Risi, Lisa M. Hanson, Carolyne Bird, Linda L. Mitchell, Elaine X. Wooton, Donna O. Eisenberg, Thomas W. Vastrick, Marie E. Durina, Kathleen Annunziata Nicolaides, Khody R. Detwiler, Tobin Tanaka, Larry A. Olson, Zain M. Bhaloo, Peter Tytell, Timothy A. Campbell, and Mark T. Goff.  
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ASQDE 2020 Online Conference

ASQDE logoThe 78th Annual General Meeting of the American Society of Questioned Document Examiners (ASQDE, Inc) was held August 10th through 14th, 2020.  It was a new type of meeting necessitated by the COVID-19 pandemic.  The meeting was originally planned to be held in Frankenmuth, Michigan but a (very wise) decision was made to hold an entirely virtual meeting instead.  The theme for this year was “Future-Proofing Questioned Documents”.
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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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Posted on by RB Ostrum

Measurement Science and Standards in Forensic Handwriting Analysis Conference

The expression “better late than never” applies to this post. Over the span of two days in June 2013 the Measurement Science and Standards in Forensic Handwriting Analysis (MSSFHA) conference was held. It explored the (then) current state of forensic handwriting analysis, aka, forensic handwriting examination (FHE). Presentations varied in content but most discussed recent advancements in measurement science and quantitative analyses as it relates to FHE.

NIST Forensic logo

The conference was organized by NIST’s Law Enforcement Standards Office (OLES) in collaboration with the AAFS — Questioned Document Section, the ABFDE, the ASQDE, the FBI Laboratory, the NIJ and SWGDOC.

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