The 2014 ASQDE–ASFDE conference included an interesting panel discussion with the title “Conclusions… Signature and Handwriting Conclusion Terminology and Scales”. I was fortunate to be able to take part, albeit only remotely via Skype.
The abstract for the session was as follows:
A current and global issue in our field is the topic of conclusion terminology and conclusion scales, particularly in respect of signature and handwriting conclusions. It is an important yet difficult topic to address because, while there is some commonality in the conclusion scales used in different geographical regions around the world, within a number of geographical regions there are multiple scales in use. It is for this very reason that it is also a topic in great need of discussion and there is a strong argument that we should attempt to reach a consensus (even if the result is that we agree to disagree).
This panel discussion is a collaboration of insights from numerous colleagues in our field in person, via Skype and in writing from private and government laboratories in geographical regions across the Americas, Australia, Asia, Africa, the Middle East and Europe.
The participants were selected to provide different perspectives from around the world, in public labs and working privately. The views presented and discussed were those of the individual and did not necessarily represent the official position of their employer or anyone else. The participants included (and I hope I haven’t missed anyone):
- Sandra Ramsey Lines (USA; private) – moderator and presenter of the introduction, “A Brief History of the Standardisation of Handwriting Opinion Testimony”
- Tom McAlexander (USA; retired govt)
- Ted Burkes (USA; govt)
- Brent Ostrum (Canada; govt)
- Dr. Audrey Giles (UK; private, ex govt)
- Bob Radley (UK; private)
- John Welch (UK; private, ex govt)
- Anna Molin (Sweden; govt)
- Wil Fagel (Netherlands; govt) – written submission only
- Charles Berger (Netherlands; govt)
- Dr. Abdulaziz Al-Musa Alkahtani (Saudi Arabia; govt)
- Saqar Alzaabi (Oman; govt)
- Gideon Dabi (Nigeria; govt)
- Jannie Bester (Sth Africa; private)
- Linda (Ning) Liu (China; govt)
- Patrick Cheng (Hong Kong; private, ex govt) – written contribution only
- Chris Anderson (Aus; private, ex govt)
- Dr. Steven Strach (Aus; private ex govt)
- Kylie Jones (Aus; govt)
Most of the participants provided a written paper corresponding, to some degree, with their oral presentation. I have embedded my own presentation below for your reading pleasure:
UPDATE: Just to clarify some aspects of this presentation, the included table (see page 4) was provided as an example relating ‘support’ for each proposition to the final opinion. While this helps to understand the structure of the likelihood-ratio, the table contents were not intended for practical application. Ideally, examiners should express their belief about the findings by assigning a value to each probability. Ultimately, those probabilities lead to the likelihood-ratio (or Bayes Factor) which can be translated into an opinion that speaks to the relative support provided by the findings for the propositions under consideration.