Length Independent PAC-Bayes Bounds for Simple RNNs

International audienceWhile the practical interest of Recurrent Neural Networks (RNNs) is attested, much remains to be done to develop a thorough theoretical understanding of their abilities, particularly in what concerns their learning capacities. A powerful framework to tackle this question is the one of PAC-Bayes theory, which allows one to derive bounds providing guarantees on the expected performance of learning models on unseen data. In this paper, we provide an extensive study on the conditions leading to PAC-Bayes bounds for non-linear RNNs that are independent of the length of the data. The derivation of our results relies on a perturbation analysis on the weights of the network. We prove bounds that hold for β-saturated and DS β-saturated SRNs, classes of RNNs we introduce to formalize saturation regimes of RNNs. The first regime corresponds to the case where the values of the hidden state of the SRN are always close to the boundaries of the activation functions. The second one, closely related to practical observations, only requires that it happens at least once in each component of the hidden state on a sliding window of a given size

Early formative objective structured clinical examinations for students in the pre-clinical years of medical education: A non-randomized controlled prospective pilot study.

BackgroundThe value of formative objective structured clinical examinations (OSCEs) during the pre-clinical years of medical education remains unclear. We aimed to assess the effectiveness of a formative OSCE program for medical students in their pre-clinical years on subsequent performance in summative OSCE.MethodsWe conducted a non-randomized controlled prospective pilot study that included all medical students from the last year of the pre-clinical cycle of the Université Paris-Cité Medical School, France, in 2021. The intervention group received the formative OSCE program, which consisted of four OSCE sessions, followed by debriefing and feedback, whereas the control group received the standard teaching program. The main objective of this formative OSCE program was to develop skills in taking a structured medical history and communication. All participants took a final summative OSCE. The primary endpoint was the summative OSCE mark in each group. A questionnaire was also administered to the intervention-group students to collect their feedback. A qualitative analysis, using a convenience sample, was conducted by gathering data pertaining to the process through on-site participative observation of the formative OSCE program.ResultsTwenty students were included in the intervention group; 776 in the control group. We observed a significant improvement with each successive formative OSCE session in communication skills and in taking a structured medical history (pConclusionOur findings suggest that an early formative OSCE program is suitable for the pre-clinical years of medical education and is associated with improved student performance in domains targeted by the program