In a recently published guideline for evaluative reporting in forensic science, the European Network of Forensic Science Institutes (ENFSI) recommended the use of the likelihood ratio for the measurement of the value of forensic results. As a device to communicate the probative value of the results, the ENFSI guideline mentions the possibility to define and use a verbal scale, which should be unified within a forensic institution. This paper summarizes discussions held between scientists of our institution to develop and implement such a verbal scale. It intends to contribute to general discussions likely to be faced by any forensic institution that engages in continuous monitoring and improving of their evaluation and reporting format. We first present published arguments in favour of the use of such verbal qualifiers. We emphasize that verbal qualifiers do not replace the use of numbers to evaluate forensic findings, but are useful to communicate the probative value, since the weight of evidence in terms of likelihood ratio are still apprehended with difficulty by both the forensic scientists, especially in absence of hard data, and the recipient of information. We further present arguments that support the development of the verbal scale we propose. Recognising the limits of the use of such a verbal scale, we then discuss its disadvantages: it may lead to the spurious view according to which the value of the observations made in a given case is relative to other cases. Verbal qualifiers are also prone to misunderstandings and cannot be coherently combined with other evidence. We therefore recommend not using the verbal qualifier alone in a written statement. While scientists should only report on the probability of the findings -and not on the probability of the propositions, which are the duty of the Court -we suggest showing examples to let the recipient of information understand how the scientific evidence affects the probabilities of the propositions. To avoid misunderstandings, we also advise to mention in the statement what the results do not mean. Finally, we are of the opinion that if experts were able to coherently articulate numbers, and if recipients of information could properly handle such numbers, then verbal qualifiers could be abandoned completely. At that time, numerical expressions of probative value will be appropriately understood, as other numerical measures that most of us understand without the need of any further explanation, such as expressions for length or temperature.

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While forensic science is generally focused on associating a trace to its source, trace's relevance is best addressed at the activity responsible for its genesis. Recurring studies show the potential of the Bayesian approach in order to address activity level's propositions in a rational and transparent manner. The objective of this research is to identify and review literature and models for transfer traces to create a relevant database for activity level interpretation. As of December 17 th , 2020, a thorough review of 2042 existing peerreviewed publications and studies concerning transfer traces has been conducted. The data have been classified by different criteria such as, the type of trace, year of publication, and type of study (i.e. population). Every publication has been critically analyzed according to its relevance, among others, with regards to a Canadian environment. This process identified research that needed to be completed. A database collecting publication and data on activity level assessment has been created. This database is available for consultation to laboratories, police agencies, lawyers and universities, thus contributing to the transparency of the expert opinion. RÉSUMÉ Alors que la science forensique se concentre g en eralement sur l'association d'une trace a sa source, la pertinence se situe plus g en eralement au niveau de l'activit e responsable de sa gen ese. Des etudes r ecurrentes montrent le potentiel de l'approche bay esienne afin d'aborder les propositions au niveau de l'activit e de mani ere rationnelle et transparente. L'objectif de cette recherche est d'identifier et d'analyser la litt erature concernant les traces de transfert afin de cr eer une base de donn ees pertinente pour l'interpr etation au niveau de l'activit e. En date du 17 d ecembre 2020, une analyse de 2042 etudes existantes concernant les traces de transfert a et e effectu ee. Les donn ees ont et e class ees selon diff erents crit eres tels que le type de trace, l'ann ee de publication et le type d' etude (p.ex. population). Chaque publication a fait l'objet d'une analyse critique en fonction de sa pertinence par rapport, entre autres, a l'environnement canadien. Ce processus a permis d'identifier des recherches a compl eter.