Human Factors in Forensic Handwriting Examination

EWGHFHE coverOne of the projects I have 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.

The final report has been published as a NIST Interagency/Internal Report (NISTIR #8282), as of February 18, 2020.1

The report abstract reads, as follows:

For some 6,000 years, humans have made an indelible mark on history through the loops, strokes, and other characters that constitute the written form of language – handwriting. The study of handwriting is also an important part of forensic science. By analyzing the characteristics of a handwritten note or signature, a trained forensic document examiner may be able to extract valuable information for determining whether a note or signature is genuine, as well as the likely writer. As with all human endeavors, handwriting examination is not immune to errors. In June 2015, the US National Institute of Standards and Technology convened the Expert Working Group for Human Factors in Handwriting Examination to conduct a scientific assessment of the effects of human factors on forensic handwriting examination with the goal of recommending strategies and approaches to improve its practice and reduce the likelihood of errors. This report provides a comprehensive discussion of how human factors relate to all aspects of handwriting examinations including communicating conclusions to all relevant parties through reports and testimony. The report also discusses education, training, and certification as well as the role of quality assurance, quality control, and management in reducing errors.

The document is not perfect (this type of thing rarely is).  However, a lot of effort went into it and the end result deserves careful consideration and review by forensic practitioners and anyone interested in the field.

You can get more information from the NIST Webpage:
Alternatively, here is a direct link to report:


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 

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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Prior odds — their meaning and significance

The concepts of ‘prior odds’, a.k.a., prior probabilities or simply priors, and ‘posterior odds’ come up in most discussions about the evaluation of evidence.  The significance and meaning of both terms becomes clear when viewed in the context of a “Bayesian approach”, or the logical approach, to evidence evaluation.  That approach has been discussed at length elsewhere and relates to the updating of one’s belief about events based upon new information.  A key aspect is that some existing belief, encapsulated as the ‘prior odds’ of two competing possibilities or events, will be updated on the basis of new information, encapsulated in the ‘likelihood-ratio’1 (another term you will undoubtedly have seen), to produce some new belief, encapsulated as ‘posterior odds’ about those same competing possibilities.

But what precisely do these terms, ‘prior odds’ and ‘posterior odds’, mean and how do they relate to the work of a forensic examiner?
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Propositions — key to the evaluation process

One of the key elements in the logical approach to evidence evaluation are the propositions used for the evaluation. They are, in a certain sense, the most important part of the whole process. At the same time, they are also one of the least understood.

Scales balancing Evidence

Today’s post explores the concept of propositions. I will attempt to describe what they are, how they are used, why we don’t change them once set and why they matter so much, among other things… all from the perspective of forensic document examination (though also applicable to other forensic disciplines).
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Certification — ABFDE

What is certification? In my opinion professional certification is a designation that indicates the holder of the certification has appropriate and adequate qualifications to do some particular, generally well-defined, job or task. As an example I am a forensic document examiner and I have received professional certification from the American Board of Forensic Document Examiners, Inc.


An internet search for ‘certification’ produces a huge list of possibilities, with more such programs being developed all the time as people become attuned to issues of quality and competency. Indeed, almost every profession has some type of certification and a few have several (consider all of the ‘certifications’ in the computing industry). Most, if not all, certification programs are aimed at improving the quality in a given profession by setting minimum standards for the job. The basic idea is that someone meeting or exceeding those standards will produce quality output on the job. Certification programs are generally created or are administered by a professional society, a college or university, or some private body set up expressly for that purpose.

Forensic Document Examination is no exception so it may be worthwhile discussing certification options as well as the pros and cons that I see for those options.
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