"Expert evidence is often a key element in the proof of claims in court.  While the reliability of certain kinds of expert opinion evidence has come under increasing scrutiny, other kinds (seen to be based in objective “hard science”) have continued to be accepted without much scrutiny. This course is for legal professionals who want to develop skills in identifying strengths and flaws in expert reports and testimony of all kinds.  Dr. Dror and Dr. MacLean will explain research findings about human cognition and how they show that expert opinion may be affected by extraneous information or unconscious bias. The course will be of use both in working with your own expert witnesses and in challenging the expert evidence tendered by the other side."
The Honourable Lynn Smith, QC,
Supreme Court of British Columbia (retired) and Honorary Professor at the U.B.C. Faculty of Law. 

"Expert evidence is increasingly important as the reach of science and expertise becomes even greater. We rely on experts for that expertise, but are there dangers of which we ought to be aware of? Dr. Dror gives a fascinating and important account of how expert opinion may be affected by extraneous information or unconscious bias. It should not be missed by anyone with an interest in the area."
The Right Honourable Lord Justice Brian Leveson
President of the Queen’s Bench, London UK​​.

Dr. Carla MacLean received her Ph.D. from the University of Victoria and her publications and training focus on memory, as well as, judgement and decision making in investigative contexts. She researches professional decision making and memory, confirmation bias/tunnel vision, and investigative interviewing techniques. Dr. MacLean co-developed the Self Administered Witness – Interview Tool (SAW-ITTM). The SAW-IT is a written witness questioning tool proven to elicit more accurate information from witnesses than traditional methods. This tool also offers unbiased method of handling witnesses post-event. Dr. MacLean is faculty at Kwantlen Polytechnic University in Surrey, British Columbia, an adjunct faculty member at Simon Fraser University in Burnaby, British Columbia, and is as associate consultant and researcher for Cognitive Consultants International (CCI-HQ).  

More information is available at: Dr. Carla MacLean.   ​Contact: contact​ 

Dror expert witness

Expert Evidence on Trial: Unearthing Bias in Expert Testimony


Total Course Length:  6 hours (including 1 hour of professional ethics).

Course on the 17th of November 2023, Continuing Legal Education Society of British Columbia, Vancouver. ​​

Course Chairs

​The Honourable Lynn Smith, KC - Supreme Court of British Columbia (retired) and Professor at the U.B.C. Faculty of Law
Dr. Itiel E. Dror – Cognitive Neuroscience Researcher, Cognitive Consultants International (CCI-HQ) 
Dr. Carla L. MacLean – Psychology Faculty, Kwantlen Polytechnic University, Surrey

Who Should Attend: 
Lawyers who work with experts from all disciplines and sectors. 
Professionals who are seeking (i) knowledge and skills to identify and expose conscious and unconscious bias in expert judgement, and (ii) strategies to effectively show the bias in opposing counsel’s experts and (iii) approaches and ways to advise their own experts so as to strengthen the quality and impact of their testimony. 


Course Reviews: 

The Honourable Lynn Smith, OC, KC:  After practising law with Shrum, Liddle and Hebenton and serving as Professor and Dean of Law at the U.B.C. Faculty of Law, Lynn Smith was appointed to the Supreme Court of British Columbia in 1998. She sat as a Justice of that Court until her retirement in September 2012.  She has returned as an Honorary Professor to the Allard School of Law and teaches a seminar on Charter Litigation. She continues to be active in judicial education, on subjects relating to the Canadian Charter, evidence and fact-finding, and sexual assault law.  She was named a Vancouver Y.W.C.A. Woman of Distinction in 1992.  She received the Georges Goyer Award from the B.C. Branch of the Canadian Bar Association in 2003 and an honorary doctorate from Simon Fraser University in 2004.  The U.B.C. Law Alumni Association in 2016 gave her a Lifetime Achievement Award. In 2020 she was named an Officer of the Order of Canada. 

Coffee and Networking Break: 14:30 - 14:45 

Ethical Issues 14:45 – 15:45
This section will explore the ethical aspects of how legal counsel can support an expert in their duty to be impartial and unbiased. 

Closing Remarks, The Honourable Lynn Smith, KC: 15:45 – 16:15.

Additional Resources

         1. "Experts on trial: Unearthing bias in scientific evidence", published in University of British Columbia Law Review (2020). 

         2. Brief Overview of Cognitive Bias 

​         3. Bias and Expert Witnesses for the Court: Article in the Judges Journal and article in the journal Science 

         4. Sources of bias

         5. Video



About the Presenters

Dr. Itiel Dror received his Ph.D. from Harvard University and is a prominent academic in the field of judgement and decision making who has published over 150 peer-reviewed scientific articles, cited over 11,000 times (source: Google Scholar). Dr. Dror has appeared in court as meta-expert (an expert on expert bias) in a number of countries (both for the defense and the prosecution), as well as trained lawyers and judges on these issues. His speciality is in taking the most theoretical scientific understanding of the human mind, brain and cognition, and translating it into practical and tangible ways to improve human performance in real world domains. A hallmark of Dr. Dror’s research is that he works with professional populations and his reputation as an expert in the field of decision making and bias. Dr. Dror is the principal consultant and researcher for CCI-HQ (Cognitive Consultants International)
More information is available at: Dr. Itiel Dror

​Contact: contact

Expert testimony

Course Overview

Is fingerprint evidence, DNA or other forensic and scientific evidence indisputable? What about a subject matter expert with 30 years of experience? "Expert" is a term people often incorrectly equate with concepts such as "objectivity" and "impartiality." This course is designed for legal professionals who want to develop the knowledge and skills to identify and reveal strengths and flaws in expert reports and testimony. Lawyers will develop the knowledge and skills to effectively communicate and demonstrate these aspects of expert judgement to decision makers. This course will also enhance lawyers’ abilities to make sound decisions regarding the quality of the testimony of their own, as well as opposing counsel’s, experts.  

Topic Background: Humans dynamically process information, which affects what we perceive, how we interpret and evaluate it, and our decision making process. Thus, to effectively identify, reveal, and communicate the value of expert evidence to the court one needs to take into account the role of the human mind and cognitive factors. Research has well established that honest, competent and hardworking experts do not always provide impartial evidence. It has been clearly demonstrated that in real casework and investigations, experts’ perceptions and judgements are affected by many different types of psychological contaminants, unconsciously introduced by the workings of humans’ cognitive system, features of the job and/or the role of being an expert witness for the court. Research and casework have shown that such cognitive biases can even impact the best of scientific evidence, such as forensic fingerprinting and DNA. 

Factors that limit the objectivity of an expert’s decisions are well documented in the literature on human cognition and law. However, there is a paucity in legal training regarding how legal professionals may effectively approach and advise their experts in order to minimize bias, as well as to communicate the issue of expert bias in court. It is precisely this lack of training regarding how one should reveal and communicate the limitations and biases of experts that this course was designed to address. This engaging and interactive course will teach legal professionals how to demonstrate to the court the “best practice” methods that they employed to mitigate biased decisions from their own experts and expose sources of bias in opposing counsel’s experts.

Learning Objectives: 

  • Learn, through presentation, discussion, and multiple interactive activities, how to communicate to decision makers the fundamentals of how information and knowledge is perceived, interpreted, and evaluated by experts to the court. 
  • Describe how to advise and manage experts so that their decisions may be more evidence-based and less biased. 
  • Know how to persuasively demonstrate to decision makers the pitfalls and errors that can occur in expert judgement and evidence. 
  •  Learn to communicate the best “practice methods” that you employed to mitigate biased decisions from your own experts and reveal the ways that opposing counsel’s experts are not impartial. 

Skills Developed: 

  • Strategies regarding how to properly engage and communicate with an expert to get the strongest possible report.
  • Application of knowledge in order to insightfully cross examine opposing counsel’s expert, i.e., features and factors that indicate bias in reports and testimony.  
  • Application of knowledge to support your expert in providing information that is resistant to an attack from opposing counsel on the grounds of potential cognitive contamination.   ​

​In sum, the course will teach the skills to identify and minimize the potential of bias in communication, personal relations, problem solving, as well as information collection and interpretation.​

Course Outline

No prior knowledge of cognition is required. This one-day course covers a variety of issues specifically chosen as relevant to enhance the work of legal professionals using experts. The course will present the cognitive mechanisms used by experts in evaluating information. It will then demonstrate their weaknesses and vulnerability to cognitive bias. These will be applied to specific issues and examples for professionals to work with throughout the day. Attendees will leave with the skills to expose bias in expert evidence and to advise their own experts so as to strengthen the quality and impact of expert testimony and thereby assist courts in coming to well-informed and accurate conclusions.

Learning Level: All levels​


Opening Remarks by The Honourable Lynn Smith, QC: 9:00 – 9:15

Domain Applications: 9:15 -10:30
Domain Applications will connect knowledge of cognitive bias to a variety of expert decision making issues. 
Broad Application. Professionals will lean to identify in expert evidence, and then persuasively communicate to the court, how issues of information processing (i.e., Knowledge representation, Allocation of resources, Perception, Judgement and Decision making) and the architectural constraints in cognition (i.e., Limits in information processing load, Malfunctions, and Lack of control) affect expert decision judgement. 

Coffee and Networking Break: 10:30 – 10:45

Domain Applications Cont: 10:45 – 12:15
Specific Application. Lawyers will learn how to demonstrate to decision makers how the following features of expert decision making are likely to have affected expert evidence. 
        a.  Cognitive perseverance 
        b.  Confirmation bias
        c.  Self-fulfilling prophecies 
        d.  Contextual influences 
        e.  Escalation of commitment 

Lunch 12:15 – 13:00

Domain Implications: 13:00 – 14:30
Although real world examples will be employed in the previous section to illustrate concepts, Domain Implications will focus on tying Domain Applications to specific issues that are common regarding expert testimony for the court. For instance, how to identify and communicate if experts’ decisions are affected by features such as base rate information, i.e., what is typical for that expert; case specific information, i.e., what was shared with the expert prior to rendering a judgement; and allegiances, i.e., what relationships are top of mind for the expert. 

In this section, participants will employ their new tool set to (i) identify underlying issues in experts’ testimony (ii) develop best strategies for advising and managing experts they are working with, and (iii) identifying sources of contamination in opposing counsel’s experts.