BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20260205T235445EST-8472LaVKok@132.216.98.100 DTSTAMP:20260206T045445Z DESCRIPTION:Title: Checking the Positivity Assumption in Practice\n\nAbstra ct\n\nThe positivity assumption\, meaning all individuals can receive each treatment modality\, is fundamental in causal inference. However\, its em pirical verification is often overlooked\, presumably because of its diffi culty. After discussing the different types of violations that may occur\, this talk will show how to go beyond propensity score to verify this assu mption using the Positivity Regression Trees (PoRT) algorithm available in the R library port. Their advantages and disadvantages will be discussed\ , along with potential solutions in the case of a violation. If time permi ts\, an extension to the longitudinal and mediation context will be briefl y discussed.\n\nSpeaker bio\n\nArthur Chatton is an Assistant Professor of Biostatistics at the University of Montreal School of Public Health. His works are at the crossroad of prediction and causation\, with an emphasis on the use of super learning approaches. He aims to (i) evaluate and impro ve the quality\, usability and generalizability of predictive scores for p ersonalizing medical care and (ii) develop and evaluate new causal methods that consider the imperfection of data collected and used for applied res earch purposes.\n\nFor more information\, please visit: https://arthurchat ton.netlify.app/\n DTSTART:20260211T203000Z DTEND:20260211T213000Z LOCATION:Room 1140\, Âé¶¹´«Ã½ÍøÕ¾ College 2001\, CA\, QC\, Montreal\, H3A 1G1\, 2 001\, avenue Âé¶¹´«Ã½ÍøÕ¾ College SUMMARY:Arthur Chatton - School of Public Health - Université de Montréal URL:/biology/channels/event/arthur-chatton-school-publ ic-health-universite-de-montreal-371116 END:VEVENT END:VCALENDAR