Essay About Dr. Kevin Koo

One positive aspect of Dr. Koo’s participation in the R v Vaughan (2022) case was how she defined her suitability as an expert witness. Specifically, Dr. Koo stated that she has produced peer-reviewed articles based on studies of the effects of alcohol consumption on cognition and has worked with other experts in the field on government policies regarding alcohol consumption. By stating these achievements, Dr. Koo indicated that she has direct experience and knowledge of the effects of alcohol on thinking processes. Importantly, s 79 of The Evidence Act 1995 specifies that a witness is allowed to give an opinion if the person has specialist knowledge in a field that is based on their experience, training, or studies. Therefore, Dr. Koo’s statement can be seen as a positive aspect of her participation in the case, as it satisfies the criteria outlined in The Evidence Act and demonstrates that she has specialist knowledge which qualifies her to give an opinion on the defendant’s intent to cause grievous bodily harm.  

Another positive characteristic of Dr. Koo’s involvement in the case was the pleasant and welcoming manner in which she spoke when addressing members of the court. In detail, Dr. Koo displayed an approachable and polite demeanour throughout the time that she was giving her evidence and was described as being ‘wonderfully polite’ and ‘very friendly’ by the judge. This behaviour can be seen as a positive factor of Dr. Koo’s participation in the case, as it increases her likeability as a witness. This is important because studies have demonstrated that an expert witness’ degree of likeability correlates with the jury’s perception of their trustworthiness, where more likeable experts are seen as more trustworthy (Brodsky et al., 2009). Moreover, other studies have shown that less likeable expert witnesses are notably less persuasive, regardless of the quality of their evidence (Younan & Martire, 2021). Therefore, Dr. Koo’s friendly and approachable manner heightened her likeability as a witness, which in turn increased the likelihood that the jury would interpret her evidence as credible and persuasive.  

Conversely, a negative factor of Dr. Koo’s participation was her failure to support her opinion with any data, facts, or evidence. In detail, when the defence counsel asked Dr. Koo what her opinion regarding the defendant’s intention to harm the victim was based on, her answer was clinical experience and observations of other clients. Following this, the defence specifically asked if Dr. Koo’s opinion was based on any data, Dr. Koo answered “No, my opinion was not based on any data” and then highlighted that there was no evidence of the defendant’s blood alcohol content at the time of the incident. This is a negative aspect because, as outlined in the R v Bonython (1984) case, expert opinions must be based on data. Further, according to the ‘basis rule’ described in the Uniform Evidence Law report (Australian Law Reform Commission, 2006, p.292), experts must be able to prove that their opinion is based on facts or admissible evidence. Ultimately, as Dr. Koo admitted that her opinion was not based on any data, she breached these rules and undermined her credibility as a witness.

Another negative aspect of Dr. Koo’s engagement in the case was her frequent use of technical language. Specifically, Dr. Koo used professional jargon that was difficult for the court to understand and was eventually asked by the judge to refrain from using such language. Despite this, Dr. Koo continued to use technical terms and the prosecutor had to repeatedly ask her to clarify what she was saying. According to Chaiken's (1980) Heuristic-Systematic model of processing, complexity hinders a person’s ability to process information systematically, resulting in the use of heuristics such as stereotypes when making decisions about the information. Importantly, Cooper et al., (1996) demonstrated this effect in juror’s decision making regarding expert evidence, showing that when the expert’s evidence is complex, jurors rely on external factors to make decisions about the case. Therefore, Dr. Koo’s repeated use of technical language is a negative factor because it made the evidence difficult to understand and thus invited the use of irrelevant factors into the jury’s decision-making processes.

It is recommended that to improve the overall quality of Dr. Koo’s evidence, more practice in explaining complex concepts in simple and non-technical terms is needed. Specifically, it would be beneficial to determine points that the expert wishes to highlight when giving their evidence and find alternate ways to explain these points without the use of specialist jargon. The expert could also rehearse their testimony with the prosecution and ask if there are any terms that they think may need to be simplified before the expert goes on the stand. Additionally, it is recommended that the expert research information that is specific to the issues of the case so that when they are asked to support their opinion with data, facts, or evidence, the expert can provide a scientific basis for their opinion. Finally, it is recommended that the expert is more cautious when answering questions during cross-examination, as there were several things the expert stated (e.g., she is paid substantially higher than others; there was no blood alcohol evidence) that were not necessary and only served to discredit her as a witness.