TY - JOUR
T1 - Through the lens of legal professionals
T2 - Examining the smallest effect size of interest for eyewitness memory research
AU - Riesthuis, Paul
AU - Rassin, Eric
AU - Bücken, Charlotte
AU - Booker, Adam
AU - Chin, Jason M.
AU - Goldfarb, Deborah
AU - Deferme, Driek
AU - Otgaar, Henry
N1 - Funding Information:
The current manuscript has been supported by a FWO post-doctoral fellowship grant to the first author (1203824N), a FWO PhD fellowship grant (11K3121N) to the third author, and a FWO Research Project grant (G0D3621N) awarded to the last author.
Publisher Copyright:
© The Author(s) 2025. This article is distributed under the terms of the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/) which permits any use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (https://us.sagepub.com/en-us/nam/open-access-at-sage).
PY - 2025/7/15
Y1 - 2025/7/15
N2 - Legal psychologists sometimes provide expert witness testimony about eyewitness memory in court. In their testimony, they regularly rely on scientific findings that decision-makers (i.e., jurors, judges) likely assume are practically relevant. However, it is not yet known which effect sizes are large enough to be deemed practically relevant for the courtroom, also known as the smallest effect size of interest (SESOI). One way to estimate the SESOI is to engage stakeholders. In two studies, we recruited 97 legal professionals (e.g., defense lawyers, prosecution lawyers, judges) from the Netherlands and Belgium and presented them with hypothetical scenarios about an unarmed robbery wherein an eyewitness made different types of memory errors (e.g., misremembering a black gun). Then, legal professionals were asked how many of such memory errors they would allow before taking certain legal actions. The majority of legal professionals viewed 1–3 memory errors as practically relevant for legal decisions or actions, but this depended on the type of memory error. A nontrivial number of participants indicated that they would never undertake legal actions after a witness made memory errors. The current studies can guide the challenging task of estimating the SESOI in forensic psychological contexts that may assist future researchers.
AB - Legal psychologists sometimes provide expert witness testimony about eyewitness memory in court. In their testimony, they regularly rely on scientific findings that decision-makers (i.e., jurors, judges) likely assume are practically relevant. However, it is not yet known which effect sizes are large enough to be deemed practically relevant for the courtroom, also known as the smallest effect size of interest (SESOI). One way to estimate the SESOI is to engage stakeholders. In two studies, we recruited 97 legal professionals (e.g., defense lawyers, prosecution lawyers, judges) from the Netherlands and Belgium and presented them with hypothetical scenarios about an unarmed robbery wherein an eyewitness made different types of memory errors (e.g., misremembering a black gun). Then, legal professionals were asked how many of such memory errors they would allow before taking certain legal actions. The majority of legal professionals viewed 1–3 memory errors as practically relevant for legal decisions or actions, but this depended on the type of memory error. A nontrivial number of participants indicated that they would never undertake legal actions after a witness made memory errors. The current studies can guide the challenging task of estimating the SESOI in forensic psychological contexts that may assist future researchers.
KW - consensus study
KW - eyewitness memory
KW - legal professionals
KW - practical relevance
KW - Smallest effect size of interest
U2 - 10.1177/13657127251357630
DO - 10.1177/13657127251357630
M3 - Article
SN - 1365-7127
JO - The International Journal of Evidence & Proof
JF - The International Journal of Evidence & Proof
ER -